Skinning the Daimler Dingo - Part 2

Skinning the Daimler Dingo - Part 2

by jodonnell

There are some other panels beveled out here that would cast a local shadow on the vehicle - in this case, a medical supply box, and the latches that secure the windows and door. I draw in white rectangles in the appropriate places, add a soft black Outer Glow, and set the layer to multiply - this hides the white rectangles used to generate the effect, but keeps the Outer Glow visible. Alternately, you can just set the level "Fill" to zero.

Again, some fairly simple and self-explanatory detailing. Rivets, bolts, and the like are visible on many vehicles, and adding them in adds to the complexity and interest of the texture. Here, I simply referenced from photos where all the rivets were. Use the circular marquee tool and fill in the rivets with 50% gray on an Overlay layer as before. Again, add a Bevel/Emboss and black Outer Glow.

It is now time to start to grime up our vehicle. Using our splatter brush, we will paint some yellowish-green grime onto our vehicle. Grime will accumulate in corners and beneath overhangs (such as rivets or panels.) There will probably also be splatters elsewhere, since combat is naturally messy.

Now we will go ahead and add some more grime, but this time we will use more of a red-orange. This will also represent some rusting on the vehicle. Again, it will often accumulate beneath overhangs and open ports, where water or other gunk might flow down.

Now that our vehicle is nice and grimy, it is time to start to chip away at our metal. The edges (particularly leading edges) of our metal will suffer the most wear, with the paint being worn away to expose the metal beneath. It is extremely important in this stage to keep in mind the scale of your vehicle. If your scratches are too large for the size of your vehicle, it will begin to look more like serious denting rather than the paint being worn away. It is also important to avoid uniformity here - if every edge has an even wear line, your texture will look very stiff. There should be spontaneous breaks in the line, and it should have an inconsistent width. Also remember that the wearing is only going to happen on exposed edges - if your deep corners are worn, it will have an off-putting effect (how did it get worn anyway?) To do the chipping, I made a new metal layer like we did in step two. Then I mask it all out, and then paint white into the layer mask to gradually reveal wear. I also added a very small white Inner Glow and a very small black Outer Glow. These help add a little bit of depth to the wear. Once you are finished with painting the chipping, apply an Unsharp Mask filter to your layer mask - this will make the edges of the wear more visible, instead of looking muddy and soft.

We will now repeat the previous step somewhat. Not all edges are completely worn, but most will experience scuffing - light damage to the paint. Make a new metal layer as before, but make it a bit lighter in value this time. Paint into the layer mask the same way you did in the last step, but use a larger brush size. The coverage can be more consistent this time, since the effect will be more subtle anyhow. This layer should have a very low opacity. Finally, just like the last step, apply an Unsharp Mask to the layer mask when you are done.

We're in the home stretch now! Just a few more steps to be done. Now we are going to add mud/dirt to the vehicle. Since this is cruising around the desert, it is going to be lighter colored dust/sand/dirt that attaches to the metal, rather than dark mud like you might find in Europe. Paint a light brown on surfaces exposed to mud and dirt - typically they will be the lower surfaces on the vehicle (closer to the ground) and on leading edges (from dirt/mud/etc splashing up onto the vehicle as it drives through terrain.) Once you are done painting, add a very fine (1-2%) colored application of the Add Noise filter. This will keep the mud from being too flat.

Now we will add a second layer of detritus, this time darker. Add this layer below the previous mud layer, and paint a darker shade of brown onto your vehicle. Again, just like the last step, add a small amount of colored Noise.

We shall paint one last layer of mud. This will be the lightest color, and will be on top of both of the previous layers. Before we were painting large mud coverage; now we will paint the small stray clumps of stuff that stick to our vehicle. Paint some small dabs here and there, some on the metal and some on top of the other layers of mud. Of course, just like the last two steps, finish off by adding a faint application of colored Noise.

Time for our last step of painting! Now we are going to add some dust to our vehicle. This will be much fainter than the mud/dirt layers. Use the brush to paint some large clouds of various shaders of brown. Then, add a layer mask, and fill that with 50% gray. Apply the Sponge filter to the layer mask. This will help get the dust to form small clumps. Use Adjust->Brightness/Contrast and Levels to increase the contrast. Finally, in areas that would accumulate more dust (flat surfaces where it could rest on), use the Dodge tool on the layer mask to slightly increase the visibility. On more vertical surfaces, you can use the Burn tool on the layer mask to reduce the dust concentration. This level will have an overall low opacity.

I said that we were done with painting, but we aren't quite done with the texture yet. Although your texture may seem detailed now, it is likely that is actually a little bit blurry and muddy. Select the entire canvas and Copy Merged to grab a snapshot of your entire document. Paste this into a new layer. First, apply a very subtle degree of colored Noise - you will probably want 1% or less. The reason this will be so faint is for our next step. Use the Unsharp Mask filter to help bring out the detail you have so carefully painted. Use a relatively high Amount setting (200%+), a low Radius (0.1-1.0 pixels) and a Threshold of zero. Play with the amount until you are satisfied. Unsharp Mask is a very powerful tool that can bring out a low of detail and interest in your texture. However, remember that like any other tool, Unsharp Mask is a force multiplier - it can bring out your carefully painted details to a brilliant level, but it can also magnify any minor flaws and errors very painfully. It is likely at this point that you will want to go back and tweak certain layers, since they will look much different after Unsharp Masking the document. I set up a Photoshop action that would use Copy Merged on the document, paste it into a new layer, and then apply the Add Noise and Unsharp Mask with values I set in advance. Using actions in this way can make this tweaking stage much easier. Once you are happy with your color texture, we will move on to the final stage.

In my case, I built this model with the intention of putting it in a real-time engine (the Battlefield 2 engine in this example.) Many modern games have very advanced lighting engines, capable of increasingly sophisticated effects such as per-pixel lighting and self-shadowing. However, no game engine can yet match the power of a professional rendering application, like Lightwave. While vehicles can cast accurate shadows on themselves and their environs, the soft shadows from radiosity and occlusion that you see in reality are currently too slow for realtime. However, we can pre-calculate this and bake it into our texture. If you are building your model with the intention of using it in pre-rendered work, this step isn't neccessary, but it will greatly enhance your real-time work.

We will now use surface baking to precalculate the lighting of the texture. In your object file in Modeler, add a large sphere in a new layer. Face the normals inward, and position the object such that the middle of the sphere is in line with the ground plane for your vehicle. Delete the lower half of the sphere, and create a flat ground plane polygon by connecting all the vertices along the midpoint of the sphere. Essentially, your vehicle will be sitting on a flat plane with a dome above it. Set the dome to one material, and the ground plane to another. Make sure your vehicle is using just one surface - if you need to control smoothing on it, temporarily unweld some points. In Lightwave, set the diffuse of the ground plane surface and dome surface to zero. Increase the Luminosity of the dome to about 100-150%, and increase the Luminosity of the ground plane surface to about 25-50%. We have the ground plane slightly luminous so that the underside of the vehicle is not totally black. This might be fine for heavy vehicles like tanks, but if a vehicle can conceivably flip upside down (which our light car might) then you want to ensure the bottom of the vehicle is at least partially visible. You may also need to add some small point lights here and there for areas the light can't reach well (such as the cockpit of a vehicle, if applicable.) You also may need to edit your vehicle somewhat - you don't want to bake lighting on surfaces that would rotate, like wheels. If you have wheels, copy them and rotate them so they face upwards. Copy those wheels and assign them to a new surface with 0% Diffuse, and delete their UVs. Put those duplicate black wheels where the wheels would normally be - this is to simulate the occlusion of the wheels, since the actual wheels are elsewhere. On the vehicle surface, add a Surface Baker modifier. Set it to only bake Illumination, set it to the correct UVMap, match the resolution to your texture resolution, and check Antialiasing and Shading Noise Reduction. Remove all texture from your vehicle surface, and make it pure white, 100% Diffuse. We are not rendering the texture here because we only need the baked illumination - we could bake it with the texture if we wanted to, but that would require a re-bake every time we edited the texture. By baking it without the texture, we can just bake the illumination and use that as a layer in Photoshop. Once you have all this set up done, set your Global Lighting properties so that Shading Noise Reduction is enabled, Ambient Light is set to zero, and Radiosity is enabled and set to Monte Carlo. Let it render (it will probably take a long time), and when you are done, take the image rendered from the bake and put it on top of your image in multiply mode. Now your texture has great looking radiosity shadows, at no cost to the real-time engine.

Final Rendered Image

In-game Shot

Now, we are finally done! Texturing can be a very long process, but ultimately a good texture is what separates an OK model from a great model. It is a very iterative process, and most of your time spent will be on tweaking and re-evaluating certain parts of the texture. Ultimately however, with enough elbow grease, a good result will come out. When you are texturing, always keep in mind the "what," "how," and "why" of your surface - what is your surface made of, how is it being impacted by its environment, and why are certain parts of it the way they are (don't take anything in the appearance for granted - question each part of the design and consider why it would be done that way in a real-world situation.) With enough patience and observance, anything is texturable. Good luck on your future projects!

James O'Donnell

jeodonnell@gmail.com

Forgotten Hope Artist - www.fhmod.org