SBD Dauntless, from scratch

Looking good so far!

Wurger, Gnomey: thank you!

Today I will start working on the diffuse map:
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The color (also known as "diffuse") map is the most obvious texture, which you can find on every game model. In my models it is composed of three separate images: the camouflage, the dirt (stains, soot, etc.), and the markings (national insignia, tactical numbers, warning labels, and all other similar stuff). In this post I will compose the basic camouflage texture.

Some time ago I unwrapped the left side of this model (see this post, Figure 62-3). Now I had to complete this work, creating remaining elements of the right side, and unwrapping them on the UVMap layout. The final result looks like the model in the figure below:


For the precise mapping, I used here the color grid image, which I already used in my previous posts. Note the different square colors on the left and right wing, as well as the different letters on the right and the left tailplane.

The complete UVMap layout looks like in the figure below:


In this layout the areas occupied by each mesh are smaller than in the alternative UVTech map. However, while in the UVTech layout both wings and the tailplane are represented by their left sides, in the UVMap layout each of them has a separate place. However, some elements are intentionally placed over another. For example – the inner walls of the "letterbox" wing slats. In this layout I unwrapped their upper faces over the wing upper surface, while the remaining faces partially "touch" the wing lower surface. (In this way I ensured, that the color of these less visible elements will match the surface around them). There are some other elements, placed over the wing or fuselage in this UV layout.

I will paint the camouflage and dirt textures for this model in GIMP. First I imported the UVMap layout from Bleder, and used it as the reference picture:


Note that I have a separate UV layout for each SBD version (although they are similar to each other). All of them are grouped in a layer group named UV. To be more visible, it is applied to the underlying layers in the Multiply mode.

GIMP is a raster image editor (like the popular Adobe Photoshop). This means that at this moment you have to choose the resolution of your all color textures. (You cannot scale it up without losing the image quality, as you can in the case of vector pictures created in the Inkscape). For this model, I decided to paint all textures as 4096x4096px images. (I still remember that I for my P-40 I regretted choosing two times smaller dimensions for my color textures).

Converting the alpha channel of the reference (UV) pictures into the initial selection, I quickly painted the classic two-color Navy camouflage (as used between 1942 and 1943). First I painted the whole model in the light gray (the color of the lower surfaces). I placed this picture on the layer named Lower:


Then I painted the darker, blue-gray upper surfaces. I placed their picture above, on a layer named Upper. For the convenience, I joined both Upper and Lower layers into a group, named Camouflage (see figure above).

I exported the contents of the Camouflage layer to a file named camo.png, and tested it on the Blender model, in the Textured mode (as in figure "a", below):


In this view you should look at the all edges that are mapped as the "borders" of the UV "islands". In the enlarged view (as in figure "b", above) you can easily see the missing pixels, which are displayed as black spots. I also carefully examined the border of the camouflage colors: there is always a local excess somewhere, which you have to remove in GIMP. I did this check having Blender window on one display, and the GIMP window on another. When I saw an error in Blender, I immediately fixed it in GIMP. When the source picture "accumulated" a few of such fixes, I refreshed its image in Blender. (As long as there are no painting layers in Blender, I still prefer to correct such errors in the GIMP source file).

When the image was verified, I incorporated it into the material scheme:


As you can see, I used an Attribute node to select the proper UV mapping (UVMap). The texture image is connected to the Diffuse slot in the generic shader node group (X.Textured Skin). For the time being I mixed it with the black anti-slip strip, "filtered" (by the Clamp node) from another picture (ref-aux.png, see this post, Figure 73-9). I will use it in this way until I paint this strip on the color image. Note that Blender allows you to mix images that use different UV maps (ref-aux.png texture uses UVTech mapping). It opens interesting possibilities for precise mapping of detailed emblems (as the squadron/personal insignia).

I already checked how the upper blue-gray surface looks like in previous post (see its final renders). Thus now I focused on the lighter, lower surfaces. Most of the things look good In the full sun, so I rendered the shadowed area of the tail (figure "a", below):


Both paints used in this camouflage were non-specular (i.e. they have low reflectivity and high roughness). For such a surface in a shadow, the most visible texture is the color map. In our case (of the X.Textured Skin group), it means the color texture and the "dirt" component from the reflectivity texture. (X.Textured Skin group internally maps pixels from its Dirt slot onto the color texture, using the Multiply operator).

The technical details of the tail (rivets, seam lines, inspection doors) in figure "a", above, are dimmed and hardly visible. It seems that rendering engine has troubles with such scenes, where the harsh light is accompanied by deep shadows. Thinking how to improve this effect, I thought about one of Blender Guru tutorials, about so-called dynamic range (the difference between the darkest and the brightest point in the picture). Blender Guru explained that the problem lies not in the renderer (Cycles), but in the another area: the color management. Following its recommendation, I installed alternative color management tables in my Blender. These tables were prepared by Troy Sobotka. You can download them from the Filmic Blender project site. The setup is simple *– I just had to replace the contents of Blender datafiles\colormanagement directory with the new files, provided by Troy. Although this package was mainly intended for indoor scenes, they still can somewhat improve such an outdoor scene like mine. You can see the result in figure "b", above. The surfaces in the shadows now seems a little bit brighter and more natural. (IMPORTANT: to see it, you need a device which displays true 24-bit colors. For example - it can be an LCD display that uses the IPS technology. The less expensive LCD monitors, like those used in typical laptops, display only 18-bit colors).

When I started preparing references (archival photos) for the next color texture (the "dirt image"), I realized that the actual dirt pattern from my reflectivity map does not match the reality:


Of course, the archival photo on the left reveals a lot of soot streaks and other dirt, which I still have to paint. Nevertheless, the overall pattern visible on the real outer wings significantly differs from the pattern on my model (you can see it in the right picture). There were no soft "traces" along the rivet seams, as I painted on my model. The panel lines were more emphasized (some of them by the thick streaks, but this detail I will paint in the next post).

Actually, the whole dirt on my model comes from the reflectivity texture (ref-details.png image). As you can see in the scheme from my previous post, I connected the inverted content of my ref map to the Dirt slot. (Internally, pixels from this slot are multiplied with the pixels from the Diffuse slot – i.e. from the color map). Following these findings, I modified the source of the ref-details.png image – the Ref-Details layer in Inkscape:


You can find this picture in the Inkscape source file that accompanies this post. I modified it by reducing the opacity of soft traces along rivet seams (the Blur sublayer), while increasing visibility of the panel lines (the Grunge sublayer). The white highlights of the rivets, which look good on the darker upper surfaces, disappear now on the lighter bottom of the wing. Thus I modified this element, adding there an additional clone of the rivets seams. I set its color to into black (using SVG filters), and clipped (using SVG mask feature) to the areas of the bottom wing and lowest parts of the fuselage.

You can see the effects of this new ref/dirt texture in the figure below:


All the technical details are more visible now. The delicate soft treads along the rivet seams still appear in the shadowed areas, but vanish in the harsh light:


In overall, this model seems to be cleaner than it was at the end of the previous post. (It looks like a factory-fresh aircraft). I will work on this issue (by adding more dirt and weathering), and report my progress in two weeks.

In this source *.blend file you can evaluate yourself the current version of the model, and here are the Inkscape and GIMP source files of its textures. Because of the large size of the original GIMP file (*.xcf), this post is accompanied by its smaller version (2048x2048px), packed into *.zip file. I think that such a version is sufficient for checking all the details of this image (the structure of its layers, their opacities and mixing functions). The resulting textures (4096x4096) are packed into accompanying Blender file.

Lovely work so far!

Wurger, Gnomey - thank you!
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In this post I will work on the weathering effects of the color texture, while in the next one I will add scratches and some other remaining details.

The weathering effects that you can observe on the aircraft from WWII era are quite "dramatic". The paints used in mid-20th century were not as chemically "stable" as the contemporary coats, thus they could change their hues in few months of intense service. The archival color photos below show an extreme case of this effect:



These photos were taken by Frank Sherschel on 14th November 1942, for the "Life" magazine. The SBD-3s depicted on the pictures belonged to VMSB-241 squadron, stationed at Midway in that time. Marines received these aircraft in July 1942, but all of them were already used before - most probably on the U.S. Navy carriers. I think that in November 1942 these SBDs had accumulated about 10-11 months of the war service. I will use them as an extreme case of the weathering. (It is always good idea to recreate such an ultimate case in the texture, because you can always make your model "newer" by decreasing intensities of the weathering layers. On the other hand, you cannot use more than the 100% of their intensities, thus you cannot make your model "older" than you initially painted).

Having historical color photos of several airplanes used by the same squadron, you can easily determine the general pattern of the stains, smudges and scratches. This pattern repeats with some random variations on every aircraft. It seems that such a radial engine like R-1820 emitted a lot of oil – in their exhaust fumes and in the air flowing from the NACA cowling. (Because of the high "oil consumption" of the R-1820 the oil tank in the SBD was quite large). The non-specular paint of the two-color Navy camouflage absorbed this oil mixed with the soot from exhaust fumes, creating characteristic dark traces along the fuselage and the center wing. The crew most often walked on the center wing, thus you can see on its upper surface the lighter traces along dome rivets seams and darker, "trodden" spaces in between. There are also some scratches in the paint. Some of them exposed the yellow primer, while the others reached the bare metal of the aircraft skin. (Thus I assume that the first layer of the Douglas primer had a yellow/orange color).

You can also notice some white splashes on the outer wings (traces of the coral sand from the atoll?), as well as the repainted areas around the tactical numbers. (On a black-and-white photo, it would be extremely difficult to distinguish these repainted areas from the oil/fumes traces).
What is interesting – in spite of the non-specular camouflage of these aircraft, you still can see a specular highlight at the wing root (as in figure "b", above).

The key elements of the weathering effect still depend on the technical details of the aircraft skin: rivets and panel seams, bolt heads, inspection doors. However, their pattern is so random, that I cannot recreate them in the SVG image, as I did in the case of the reflectivity map. Thus we need a reference picture of the skin details for painting the color (diffuse) texture. It has to be mapped in the same UV layout (UVMap) as the color texture. To do this, I composed from the key layers of the SVG drawing an auxiliary image, mapped in the UVTech layout. Then I quickly transformed it into UVMap layout using the Bake feature:

The old Blender Renderer engine is a better tool for such a direct transformation of a single texture than the Cycles Renderer. In the Blender file that accompanies to this article, I created a dedicated screen layout for this purpose. It is named Texture Baking. You can find there a simple script that I used to switch the UV layout of all model meshes between UVTech and UVMap. To bake a texture from UVTech to UVMap layout, you have to switch the current rendering engine to Blender Renderer and disable nodes in the B.Skin.Camouflage material. Then assign the image (mapped in the UVTech coordinates) to its single Blender Render texture assigned to B.Skin.Camouflage material, named Image for Baking. When you click the Render:Bake button, it will generate the resulting texture (in the UVMap coordinates) in the Test image, which you can see in the UV/Image Editor. You can use Image:Save As command to save it to an external raster file.

Click to expand...

I created such a reference image for each SBD version I have modeled (SBD-1, SBD-3, and SBD-5), and placed all of them in GIMP:



The darker areas in this weathering appear between the rivets seams. I decided that it will be easier to recreate them using one layer of darker camouflage color, overlaid by partially opaque layer that contains the weathering pattern (in white). First I painted in this way the right outer wing:



I used this "sample" for testing if such a pattern looks good in the final image:



I think that it looks acceptable. Thus I started to paint in this way the weathering of the whole upper surface.
I create the basic pattern of the lighter traces along rivet seams in four steps:



First I painted the "overall noise" with an "acrylic brush" tool (figure "a", above). Then I changed the tool shape to "pencil" and draw thin lines along rivet seams (figure "b", above). In the next step I used Eraser to make this pattern more random (figure "c", above). Finally, I filled it again with light touches of an irregular brush, to lighten the overall effect (figure "d", above). (This last step is optional, depends how this fragment looks like on the reference picture).

Figure below shows the resulting weathering pattern on the fuselage:



As you can see, it differs from the pattern on the center wing. The lighter traces along rivet seams are thinner, the color is more uniform. Using a separate layer, I added a yellow tint to the darker areas.

Unfortunately, in Frank Sherschel's collection there is only one, small photo which shows the bottom surfaces of an SBD from this squadron:



You can identify there some smudges on the outer wing and rear fuselage. However, you cannot determine the dirt pattern for the center wing and the engine cowling. (You can only say that they are dirty).

Well, in this case I had to use another, black and white photo as the reference. This photo shows clearly the center wing section of a typical aircraft:



As you can see, I recreated in my image the exact copy of the smudges from this SBD-4 center wing. They are placed on another layer (Flow) in the Stains layer group.

Finally, I enriched this basic dirt pattern with all the additional details visible on the reference photos: white "burnouts" on the fuselage sides, discrete traces of soot. There are also irregular, darker lines along some of the panel seams:



Each of these elements has its own color and layer. Note that the darker lines along panel seams extend across the upper and lower surfaces. I painted them using the same color, but on the bottom surfaces they are more transparent, to obtain the appropriate contrast. (Painting them, I used a 50% opaque mask for the bottom surfaces).

Figure below shows this "weathered" diffuse texture on the model:



Frankly speaking, I am still not satisfied with these results. This weathering requires some minor adjustments. For example: on the reference photos it has a slightly different hue. The fuselage below the tailplane also requires some fixes.

While painting all these weathering effects, I came to conclusion that I cannot re-use them without any modification in the three-color camouflage, used in the SBD-5s and -6s. Thus I will not split the color texture into three interchangeable parts, as I announced in my previous post. I will have to prepare few alternate color textures instead:

• A colorful pre-war painting scheme (orange wings!), without weathering for the brand-new SBD-1s from the Marines squadrons (+ eventually the later single Light Gray color scheme, as visible in color photos preserved in the Smithsonian Air And Space Museum);
• Two-color Navy scheme for the SBD-2,-3 and -4s (described in this post);
• Three-color semi-gloss Navy scheme for SBD-5s and -6s (+ eventually the white variation of this for the SBD-5 and -6 scheme, using on the Atlantic areas);

Of course, I will reuse fragments of the weathering pattern described here in the three-color scheme for the SBD-5s and -6s. However, before I do it, I have to finish this color texture. Thus in the next post I will fix the minor flaws described above, and recreate the scratches visible on the reference photos. Then I will apply the "decals" – national insignia, tactical numbers, etc.

In this source *.blend file you can evaluate yourself the current version of the model, here is the GIMP source file of its textures. Because of the large size of the original GIMP file (*.xcf), this post is accompanied by its smaller version (2048x2048px), packed into *.zip file. I think that such a version is sufficient for checking all the details of this image (the structure of its layers, their opacities and mixing functions). The resulting textures (4096x4096) are packed into accompanying Blender file.

Estimado M.J.
Maravilloso trabajo y resultados, hasta ahora...

Regards

Great work so far!

Wurger, SANCER, Gnomey - thank you!

Below another post, about specific detail: recreating the aircraft skin abrasions. To provide a complete picture to eventual other 3D modelers, I describe the "kitchen details" of the Blender node setups. (I know that it may look like a "rocket science" for those who never used it . However, this is one of the last posts about "painting". I will finish this painting phase soon, then will provide reports on more classic elements when I start to model the details: undercarriage, engine, etc.)
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It seems that Douglas used a high-quality paint for their SBDs, because I cannot find any trace of chips/flakes, even on such a worn-out aircraft as this from VSMB-241 (see figure below). However, you can see some scratches on the center wing, trodden by the crew:


In the photo above, the minor scratches are yellow, because Douglas used a yellow layer of Zinc Chromate primer below the camouflage paint. (The interiors were painted with another layer of the Zinc Chromate, mixed with Lamp Black to obtain a darker, greenish hue).

However, the larger area along the leading edge was often trodden to the bare metal, which you can see in the photo. This scratch has a typical, irregular band of the primer around its borders. In this post I will recreate these abrasions.
The aircraft producer anticipated this kind of damage (at least to some extent), placing a thick, rough, anti-slip strip along the fuselage. It seems to be made of a black, rough material, glued (?) to the aircraft skin (as in the picture above), and spans from the trailing edge to the main spar. However, the most "visited" by the servicemen area in the front of this spar had no such a cover. On some SBDs (including the one on the photo above) you can find a glossy, black continuation of the anti-slip strip. I suppose that it was added in the Navy workshops. It seems to be simply painted using a typical black paint, thus was more prone to the abrasion (as you can see in the photo).

To recreate the effects from this archival photo, I had to paint this glossy black area first. It requires changes in the two textures: color map (because it was black) and reflectivity map (because it was glossy). I created in the source GIMP file separate layers to reproduce these shapes. This way I can simply turn them off while painting another aircraft that did not have this feature (like most of the SBD-5s and -6s). Figure "a", below, shows the color texture image, while figure "b" shows the additional reflectivity map (they share the same GIMP file):


Note that I introduced here another part of the reflectivity texture: the map of the areas that are more specular than other. This is a natural addition to the ref-aux.png map that I used in this post to make the remaining anti-slip strip more rough. There are also some other areas that look more "wet" (specular) than the others. For example – the fuselage sides (because of the small amounts of the oil, spreaded from the engine). I painted them in GIMP in a lighter gray, on a separate layer named Wet area (see Figure "b", above). I saved this image to a file named ref-aux-spec.jpg. However, I could not simple merge it with the ref-aux.png map, because it uses the different UV layout (UVTech). Thus I had to join these images in Blender, using special node that mixes two grayscale pictures (as in Figure "a", below):


For the brevity I renamed the ref-aux.png file to ref-aux-rough.png. Figure "b", above, shows these updated textures on the rendered picture. Frankly speaking, the weak increase in the specularity of the fuselage sides is not visible here, but you can see the much more accented difference between the reflectivity of the forward and the rear anti-slip strip segments.

I am going to recreate the scratches that you can see in the archival photo using so-called shader mask. Thus, in addition to the weathered camouflage shader that I used so far, I need a "bare metal" shader, which looks like a rough duralumin skin. Figure below shows such a thing:


Note that this shader uses the ref_details.png image (see Figure 73-4 in this post) as the base color texture (for the Diffuse as well as the Specular colors). The dark lines from this image create appropriate shadows along the seam lines. I just made this input image somewhat darker (using a Multiple node), to transform the semi-white background color of the original ref_details.png image into metallic gray. What's surprising, it's better to use a fixed Reflectivity for such rough (low-reflectivity) metallic shaders. When I tried to use the same ref_details.png image as the reflectivity map for this case, it made the panel seams lighter, reverting the effects of the color texture.

To share the dirt between the "bare metal" and the camouflage shaders, I separated it from the color texture. I named the two resulting images as color-camo.jpg (the weathered camouflage) and color-dirt.png (the soot traces and some stains on transparent background). I used the Stack Image nodes (see Figure "a", above) to combine them with corresponding backgrounds, like the layers in GIMP. Figure below shows these two components of the color texture image:


In the color-dirt.png image I initially grouped only the soot traces. It is possible that I will also transfer other layers there. (We will see if I have to do this during the work on the pre-war "natural finish" painting scheme of the SBD-1).

Then I prepared a B/W "shader mask", painting white, feathered scratches on a black background:


As you can see in Figure "a", above, I decreased the opacity of these shader mask layers while painting, using as the reference the camouflage from the layers below. I also used a copy of the reference image (layer Rivets and seams) to precisely recreate technical details visible inside this scratch. (SBD had flush rivets on this area. Usually the paint remains on their heads even when there is bare metal around). Figure "b", above, shows the final material mask. I saved it to a file named mask-scratches.jpg.

Below you can see how I used this mask in the material scheme:


Note that I placed a Color Ramp strip between the mask and the Mix Shader node. The pattern, set in this node, controls the ultimate size of the scratches, and the width of the transition area. (The transition area is "feathered" border of these bare metal scratches, where the share of both shaders is greater than 0). For example, if I want to get the "chips" effect (bare metal areas with sharp borders) I should switch this color ramp mode from Ease to Constant. (It creates a strip that contains just sharp black and white spans, without any "gray transition" between them).

The result of this shader mask looks like the test render below:


The bare metal scratches look good on the dark background (like the anti-slip strip). For certain viewing angles they disappear in the camouflage, because of their gray color (as in Figure "a", above). Still, they can shine (as in Figure "B", above) when you view them from other sides, especially when you do it from greater distances. (This shining effect looks quite convincing – this is the advantage of this method over scratches painted directly on the color texture).

Now, let's add the primer to these abrasions! This means that we have to add yet another shader to our material scheme. It is similar to the camouflage shader, with one exception: it has to have a uniform yellow color, instead of the camouflage texture. To reuse all the other settings, I decided to "extract" the final Gloss Paint shader from the X.Textured Skin group. Figure below shows the modified material scheme:


I "cascaded" the camouflage, primer and bare metal shaders, using two Mix Shader nodes. In general, each Mix Shader could use a different mask image. In this case both use the same input mask, but each one modifies it in a different way, using its Color Ramp node.

You can see the result below:


I think that it looks good enough. These and other details bring the final effect closer to the original photo from the beginning of this post (compare the picture below with the first picture in this post):


Of course, there are still differences. (For example - I have impression, that I should use stronger sunlight in my scene, to obtain such a high contrast between the lighter and darker areas as in the original photo). Well, I will work on these issues later.

Using the shader setup presenting in this post, painting all other scratches is a breeze: you just have to add another white splash on the shader mask image.

In the next post I will prepare the "decals" texture, containing national insignia, tactical numbers, and some service labels. (I will add more of these labels during the detailing phase, when I review each area of the aircraft skin).

In this source *.blend file you can evaluate yourself the current version of the model, and here is the GIMP source file of its textures. Because of the large size of the original GIMP file (*.xcf), this post is accompanied by its smaller version (2048x2048px), packed into *.zip file. I think that such a version is sufficient for checking all the details of this image (the structure of its layers, their opacities and mixing functions). The resulting textures (4096x4096) are packed into accompanying Blender file.

Lovely work so far!

Wurger, Gnomey, thank you!
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The last texture for my model contains various elements that in the plastic kits are delivered as the decals: national insignia, radio-call numbers and various service labels. I prepared it as another vector drawing in Inkscape:


I exported this picture to a raster file named color-decals.png. It has transparent background, because I will combined this image with the other components of the color texture, prepared in previous posts.

The U.S. national insignia passed various transformations during the WWII. Between December 1941 and May 1942 the roundels on the Dauntless wings were enlarged, so they spanned over the ailerons (see figure "a", below):


However, as you can see in the photo of the USS Enterprise deck, there were exceptions: some aircraft preserved the older, smaller roundels. After 6 May 1942 all the roundels reverted to their "standard" size (72 in). Note that in this case they did not "touch" the aileron, but still their outer edge was very close to the leading edge (as in figure "b", above).

All of this means, that I cannot use for these wing roundels the same UV map as for the camouflage (UVMap). Although in this default UV layout the ailerons are in-line with the main wing surface (so they also fitted for the "decals" image), the problem occurs on the leading edge. In the UVMap layout its seam runs on the wing bottom surface, along the edge of the first panel. (I masked this seam on the camouflage texture in this way). Such a layout would split the bottom roundel into two parts – as marked in Figure "a", below):


To keep these roundels "in one piece", I had to create another copy of the default UV layout (UVMap). I named it UVDecals. Then I modified it, adding an additional seam along the leading edge, and shifting appropriate faces from the upper to the bottom surface (as in figure "b", above).

In fact, I created this new UV layout only for the two objects: the outer wing meshes. This is possible in Cycles thanks to a special "fallback" node. In my previous model I worked out a node group, which can deliver the default (UVMap) coordinates for the all meshes that do not contain the requested (UVDecals) map. Such a group greatly simplifies using alternate UV layouts. You can find it in the material scheme as the UVFallback node:


Conceptually the color (diffuse) texture is composed from three images. The Decals image is placed over the camouflage (Camo), while the Dirt image is placed over them. Technically, the X.Textured Skin node internally places the decals image over the camouflage. Thus in the scheme you can see the Dirt image placed over the Camo and Decals images (it uses two Stack Image nodes for this purpose). If you want to learn more about these group nodes, see vol. III of the "Virtual Airplane" guide).

In the GIMP source, I shifted all the Stains layers from the color-camo.jpg into the color-dirt.png (see Figure 76-5 in this post). It allowed me to use the white stains layer for recreating weathering on the roundels located on the upper wing surfaces.

The stars on the wing bottom surface were also painted inside the letterbox slat. Initially there was something wrong with my UV mapping of this element (figure "a", below):


The pictures of the star on the slat inner surfaces were distorted (shifted). To fix this issue, I copied current UV layout (UVMap) into the UVDecals layout, and then shifted some of its inner UV vertices (figure "b", above).

Below you can see the first test of the "decals" texture:


At this moment it only contains the national insignia.

Now it is the time to "personalize" this aircraft. Let's recreate the "black 4" from VSMB-241. As the first thing I added the radio-call numbers:


The single-digit number ("4") was painted using the standard stencil. There was no problem in recreating this detail using the USAAF stencil font. (In fact – its vertical "stroke" was shortened. To recreate such a shape, I transformed the text into path and made appropriate modification). Then I exported from Inkscape the resulting color-decals.png picture and placed it as the reference in the source GIMP image, above the Camouflage layers. Finally I painted the darker background behind the radio-call number on a separate layer, as a new part of the camouflage image.

Using the USAAF font I am able to quickly recreate various service labels. In fact, most of them disappeared from this war-weary "black 4". On the archival photo I can see only one label, on the life raft door (above left horizontal arm of the star – see figure "b", above). It is interesting to note how this detail appears on the restored aircraft:


As you can see, the labels on the restored aircraft are too large, and located in the wrong places. I recreated these elements in Inkscape, on a separate layer.

Restored aircraft can differ from the original in many details. In particular, their painting (the hue and the gloss of the camouflage, service labels fonts and sizes) leave much to be desired.

Click to expand...

The last elements that I have to draw my "decals" texture are: the serial number (on the fin) and the model description (on the rudder). Unfortunately, the serial number is too small to be readable on the reference image, and the rudder is clipped out of its photo frame. All we can do is to use the photo of another aircraft from the same flight (as in figure "a" below):


Among the historical photos, I had only close shots of these numbers on some SBD-5s (figure "b", above). They showed me the proper font and size of these labels. For this aircraft I could only use a random serial number (figure "c", above). I chose one of the lesser ones from the two polls of the SBD-3 serial numbers (3185-3384 and 6492-6701). I suppose that the aircraft from this first pool were delivered before December 1941. On the historical photo (figure "a", above) of another aircraft from VSMB-241 you can still see the traces of the red and white stripes on the rudder, painted in December 1941. Then, in May 1942, the rudders were covered with the standard camouflage. You still can see these stripes behind the Blue Gray paint, because it was impossible to scratch the previous paint from their fabric skin. I reproduced this effect on my "decals" texture, drawing seven highly transparent stripes on the rudder.

Below you can see the final render of the "black 4":


I also prepared for this model an alternate, sea environment:


I think that this picture of the Pacific Ocean creates a more familiar surroundings for such a naval aircraft. You can find the definition of this environment in the World tab of my Blender file. I named it Sea. Consequently, I renamed the previous environment to Land. You can easily switch between these two "worlds".

In the next post I will work on the three-color Navy camouflage, used after January 1943 (you can find it mainly on the SBD-4s and SBD-5s). I will re-use in that new color scheme most elements from this two-color painting (the dirt texture, some of its weathering). Thus it will be a much quicker work.

In this source *.blend file you can evaluate yourself the current version of the model, and here are the Inkscape and GIMP source files of its textures. Because of the large size of the original GIMP file (*.xcf), this post is accompanied by its smaller version (2048x2048px), packed into *.zip file. I think that such a version is sufficient for checking all the details of this image (the structure of its layers, their opacities and mixing functions). The resulting textures (4096x4096) are packed into accompanying Blender file.

Fantastico e interesante etapa.
I like the weathering

Saludos

Good work so far!

I envy your attention to detail and perseverance to get it right. Masterful work.

Wurger, Lucky 13, SANCER, Gnomey, Doom! - thank you!
Today I will work on another case: the tri-color Navy camouflage:
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In my previous post I finished the case of so-called "two-color" U.S. Navy camouflage, which was used between September 1941 and January 1943. You can observe on the archival photos that its non-specular Sea Gray / Light Gray combination was especially prone to weathering, and accumulated every grain of the soot and drop of the oil stains. Simultaneously the weathered Sea Gray paint became more and more white. The new, "tri-color" camouflage, introduced in January 1943, fixed these flaws, and provided better protection on the vast, dark waters of the Pacific. You can see an example of this pattern on an SBD-5 from VB-16:


However, this historical photo has a technical flaw: its colors are "shifted toward blue". You can unmistakably see this "shift" in the color of the bottom surface (it was Intermediate White). I was not able to correct this deviation, finding acceptable. Below you can see another photo of a SBD-5 from VSMB-231, which colors are more balanced:


There were two variations of the tri-color painting scheme. While the most probably the "white 35" from the first picture represents the painting applied in the factory, the photo below shows a case of another variation:


The main difference is the dark Sea Blue section below the cockpit. It is creating a "bridge" of the Sea Blue color between the upper areas of the wing and fuselage. Most probably such a camouflage was applied by the Navy workshops, when the older aircraft were repainted from the "two-color" scheme. Note that all of the SBD-5s on this photo have larger national insignia than the "white 35" from the first picture. Their stars have precisely the same size and location as those in the two-color scheme. (It seems that the workshops just painted the two rectangles on each side of an existing roundel). You can also encounter aircraft that had the "bridged" camouflage and the smaller (i.e. standard) insignia, but it seems that all aircraft without the "bridge" below the cockpit had the standard roundels. This fact seems to confirm the "workshop" hypothesis of the "bridged" camouflage origins. Many modelers think that this variant of the tri-color scheme was created in the main Navy overhaul facilities at Norfolk.

In this post I will recreate the "white 35" shown on the first picture. This particular aircraft belonged to VB-16 squadron from USS Lexington (CV-16), and was flown by Lt. (Jg) George T. Glacken, with RM Leo Boulanger at the rear gun. There is another close-up photo of this aircraft, most probably taken during the same flight (early April 1944, over New Guinea):


This SBD-5 seems to be n much better condition that the weary SBD-3 from my previous post. From the photos of the other VB-16 aircraft it seems that the crew of this squadron had enough time to take care of their machines. All of them had uniform squadron emblems, the flying staff names were painted below the cockpits, and every mission was marked with a small "bomb" on the fuselage.

Unlike on the SBD-3, on this SBD-5 the anti-slip strip ends at the main spar (there is no forward part, painted in the glossy black). There are no visible deep ("bare-metal") scratches on the center wing upper surface. Just some irregular areas and a few seams of the dome rivets are brighter. Most probably the paint was scratched from the heads fo these rivets. (There is no such a thing in the front of the main spar, because its seams were made of the "flat", countersunk rivets).

I started my work on this camouflage by creating a new copy of the previous source GIMP file (Color.xcf). Then I modified its contents by repainting some key layers. Finally I exported the resulting pictures, overwriting the existing images (texture components in the skin material of my model).

The first repainted elements were the basic layers of the camouflage (color-camo.jpg image) – as in figure "a", below. This is one of the three color texture components. I simultaneously modified the ref-specular.jpg component of the reflectivity map, providing the "gloss" to the dark Sea Blue surfaces (figure "b", below):


I left the weathering layers of the camouflage image intact (hey are the same as in my SBD-3). You can see the first test render of this new camouflage (combined with modified color-dirt.png image) below:


This first render revealed that while the non-gloss surfaces look quite convincing, I had an issue with the more glossy upper surfaces. The dirt pattern disappeared on the highlighted areas. They look unrealistic smooth and clean (like on a polished airliner!).

The remedy for this issue is yet another texture, which will "modulate" the color of the specular reflections, making some areas darker than the others. It is quite simple – a neutral gray background and just some darker splashes. I named it color-specular.jpg. Figure below shows this image and its place in the material schema:



Figure below shows the test render of this updated material:


I reproduced the scratches on the center wing in the same way as in the two-color SBD-3: using the scratches mask (mask-scratches.jpg image):


In this case the only bare-metal spots are the heads of the dome rivets. I recreated them using an inverted copy of the reference image. I also added some partially scratched areas in the front of the anti-slip stripes (they "reach" just the primer color).

Finally I prepared the "decals" picture in Inkscape, then exported it to the color-decals.png file. Analyzing various photos of other aircraft from the same squadron, I determined that the serial number on the fin was black, and small radio-call numbers ("35") were also painted on the wing upper surface. I repainted in GIMP the VB-16 emblem (it seems to be in the contemporary cartoon style). Then I exported to a *.png file, and placed it in the SVG source image as a linked picture:


Below you can see another test render, featuring the complete texture set:


In overall, the tri-color painting looks acceptable. However, this model badly needs the details: the cockpit interior, radial engine, crew… Thus, in this post I am finishing the third phase of this project ("working with textures and materials"). Now I am starting the last, fourth phase: detailing. For most of the small parts that I will create in this last phase, I will use simpler materials that do not require any UV-unwrapping and texture images. For example – on the picture above the propeller hub requires different material (in this "white 35" it seems to be painted in a glossy Sea Blue). At this moment I kept the hinges and canopy rails in the natural metal color. I will have to "repaint" them, using simpler versions of the camouflage colors. Finally, it seems that I have to improve the glass material of the cockpit canopies (comparing with the archival photos, they are too "clear"). Anyway, I will describe my solutions to all these issues in the future posts.

In this source *.blend file you can evaluate yourself the current version of the model, and here are the Inkscape and GIMP source files of its textures. Because of the large size of the original GIMP file (*.xcf), this post is accompanied by its smaller version (2048x2048px), packed into *.zip file. I think that such a version is sufficient for checking all the details of this image (the structure of its layers, their opacities and mixing functions). The resulting textures (4096x4096) are packed into accompanying Blender file.

Great !!!