Create a sci-fi car in 3ds Max - Part 2
Learn how sci-fi pro Tamas Gyerman models and textures a post-apocalyptic vehicle with 3ds Max and CINEMA 4D's Bodypaint 3D
In this tutorial we'll run through the process of creating a post-apocalyptic car design in 3ds Max. You'll learn about methods and techniques, as well as design and visual development. I will show you how to prepare your scene, create the car, detail the model's topology, and understand surfaces and geometry. Then we'll move on to texturing the car using BodyPaint 3D and Photoshop. My methods and techniques will cover UVs, texturing, and the final render.
STEP 16: Importing into BodyPaint 3D
I reopen my 3ds Max file because I must transfer it into BodyPaint 3D. It's a very simple step, using the Export option. Choose .OBJ as your file format to export to. 3ds Max gives us many presets to get a better exported file, and I choose the CINEMA 4D one. BodyPaint 3D is an internal part of CINEMA 4D, and I really like to use it.
Open the .OBJ file in BodyPaint with a single drag-and-drop action. The viewport will tell you information about the model's condition, similar to 3ds Max. I think about the normal direction, smoothing groups, and numbers of meshes. One very important thing is to check the Object Manager and the item list. In CINEMA 4D, every modifier or attribute has a tag object. Check the UV coordinate tag (the square tags) at the end of your icon – if you can't see this, something went wrong with the export options.
STEP 17: Importing into BodyPaint 3D
In the modeling stages, I separated the car's model into six different parts, and this is the reason why. I create texture groups to get a better handle on the model, UV and textures. I create these according to the UV sets and which materials are used:
- A fabric group with displacement event
- One group for pins and the fence object
- Two groups for tubes and tires
- One group for silhouettes
- One big group for the car's body
These groups have different-sized textures, from 1024* to 6144*. Earlier on I talked about the optimized UV size and pixel balance, which is also important here.
STEP 18: Material masking
The object works fine with only one colored material, but there are a few meshes which have more than one material inside. The main car group is one of them. I create material/polygon IDs to separate them, which is very simple to do in BodyPaint 3D. Push Enter on the object three times, or switch to Polygon mode (the left-hand icon of a cube with an orange top). Then click twice on the parts you need, and the software will select all the connected geometry instantly. Hold Shift to add more parts.
When you have all the required parts selected, go to the Select tab and click on Set Selection. An orange triangle will appear next to the object name in the outline editor. This is much the same as 3ds Max's Polygroups action. I can now rename the triangle and switch the materials.
Colors help me to easily create separate masks and layer folders in Photoshop. I simply use the color range and masking tools. The material groups become layer groups in Photoshop, making more layers and a bigger .PSD file, but giving a faster shading and compositing process. I think these are very necessary further down the pipeline.
STEP 19: Texture baking
I go through all the polygon selections, attaching materials as above, and get colored mask groups which fit with the model's UV. When I finish all the items' definitions, I create a Bake Object tag. Simply right-click on the name in the outliner editor, click on ‘CINEMA 4D Tags' and choose the Bake Texture icon. The Bake function works on the selected object now; by clicking on it, and you get the function tab instantly. There are so many parameters, but I think the names tell exactly how they work. The most important for me is the ‘Use Polygon Selection' command, otherwise the bake process doesn't bake all the materials as I would like.
The ambient occlusion (AO) pass is always important for texture painting. I can create it here in two ways. A simple way is to use the basic Ambient Occlusion button. Another way is to use Luminance, which is more useful for me, because it works from a material and has changeable parameters, while the straightforward AO bake option only functions with basic parameters. The AO Luminance effect can be used easily: click on the ‘Texture…' arrow icon in the material's Luminance channel, and choose Effects > Ambient Occlusion.
If you know a bit about Photoshop, you'll know about layer blending modes. There isn't a 100% overlap between the two softwares, but BodyPaint 3D's blending modes are similar. When I create textures, I try to use just the main blending functions, such as Multiply, Overlay, and Screen.
STEP 20: Tools in BodyPaint 3D
BodyPaint 3D has so many built-in brushes, colors and pattern tools. I wouldn't want to favor any over the others – all of them are useful, and I think everybody can find a fitting one to use. The painting process still functions similarly to Photoshop, with a layer hierarchy, blending modes, groups, and white/black masks. The software has an internal UVW editor which is really useful in the painting process too. This way I can easily find the UV islands I want, and also find my tools, which work similarly to in Photoshop: color range, magic wand, erase, clone, burn, etc.
Because BodyPaint 3D is an internal part of CINEMA 4D, is has a 3D viewport painting mode, which is one reason I like to use it. You can paint in 3D, and the software will project the event onto the 2D UV map/texture. The two are connected, so if I have a bad UV island, trying to paint it gives me an error. It's a good way of checking my UV mapping is correct.
So, because BodyPaint 3D works via UV islands, it has a problem with UV seams. The brushes cannot move over the cut seam parts. Instead, they must be painted to match together on each side. It's not as hard as it sounds: the software gives us a projection mode, which freezes the viewport as a 2D element and hides the seams. The brushes can now move over the seamed parts without disconnecting.
STEP 21: Selecting base textures
You can see here what kinds of base texture I'll use to create my car: many types of metal, wood, fabric, rubber, and of course solid colors (because metal is a solid color with additional details). See what kinds of details are working well for your car; think about edges, dirt, decals, leaks, mud and dust. I choose a rusted, brown metal as the base texture, and put details over it as a test, like you'd paint in real life. I never use the erase tool – white/black masks are much better.
STEP 22: Creating wear and tear
The first detail I always create is the edge wear, which I separate it into three parts. Two of them are almost invisible in diffuse colors, but are still functional in the specular map. Mid and soft edges are essential but harder to create; there are procedural ways to get a similar effect, but I paint mine manually. The high/sharp edges appear in sharp corners, and are more visible in the diffuse.
I paint all these with a simple sponge brush with jitter effect, in multiple sizes. I create a new layer and fill it with solid white, then apply a mask to it, and fill it with a black color. I then turn my brush to white and start to paint onto the mask. When I've finished painting, I change the layer's opacity to create a surface effect that works well.
STEP 23: Adding dirt and dust
In real life, dust and dirt are natural things, always sticking into joints, corners, and holes. Ambient occlusion is always a big help to find these parts, but AO has a linear shading look, while dirt has random sizes, strengths, and directional effects. So AO cannot be used alone, but must be painted manually. I create a new layer, fill it with solid brown, mask it, and paint my dust and dirt details onto it.
STEP 24: Adding base colors
A car has a fully painted surface in real life, but mine will have a rusty surface to represent neglect and environmental damage. I paint the car with two separate colors. In this case, the car's bonnet was damaged and it needed a new one, taken from another car! I fill the layer with colors and create a mask again.
There are very important brush settings to consider here: jitter randomness works well for dirt and edges, but paint erosion is much more difficult. BodyPaint 3D's brushes give so many possibilities for how the brush responds to your tablet pen: pressure, size, opacity. The car's paint has tiny, sharp, abraded edges; I do the bigger parts first, then detail the bigger patches with these tiny elements. Abrasion has hard edges rather than smooth, without falloff fades. When I'm done with the first layer of the surface paint, I duplicate it. Enhance this layer's color and shrink the mask's range. I push the differences between the top and middle paint layers to create a more saturated paint surface.
STEP 25: Decals and damage
The car looks really damaged by environmental effects, but the damage in this step is more subtle: rust, burned holes, small chips where the car has been hit by stones. I source these details from www.textures.com, where there are many textures that can easily be used for this case. Just paste, clone, and mask for the best outcome. I also use the sponge_frayed brush to paint more random-looking details onto the surface. I concentrate the bigger, general damage on the car's larger areas, and put the tiny details in more random places.
STEP 26: The car's accessories
Of course, the car is not only a body, but has other separate parts: tubes, cover plates, wooden planks, fences, and rubber. For these parts, I follow the same steps as for the main body. I create edges, dirt, dust, and damage. When creating dried-on or smeared effects, consider which parts of the car are covered or exposed.
STEP 27: Warning!
In the concept art, the car's main paint detail is the hazard stripes. I do some additional painting on the body to give it a racer look, using a simple white layer and masks. This layer is in the main paint group affected by the overall damage mask of surface paint. The hazard stripes are made from a simple texture.
I also add some skulls and typography onto the surface, like the concept art suggests. I use the 2D projection ability to get all these details onto the surface without seam breaks.
STEP 28: Mud and leaks
Leaks and mud are the final part of diffuse color painting, because these details are dictated by the others. Dirt and surface damages define the size and strength of the leaks. I paint some splashes and leaks by hand, below the pins and tiny parts, again using samples from www.textures.com. Cloning and masks works well in this case, too. I use the charcoal_chunky brush in a brown layer to get the mud effect. I also use this brush alpha with the Burn tool to get details into the solid brown paint.
STEP 29: Control maps
When I've finished the diffuse map, I have to create additional textures to give a good look to my content. Shaders work with multiple numbers of textures, e.g. specular color, glossy, roughness, reflect, bump, normal, transparency, etc. These are all based around the diffuse. Normal maps are created for high-resolution geometry, such as character sculpts. Specular color is a saturated type of diffuse color, plus it has additional colors, if that type of material needs it. Glossy and reflect maps are always monochrome. Bump is monochrome too, the normal map built up by three color components.
There cannot be any fully ‘clamped' pixels in these control maps, meaning there are none fully black or fully white, since pure black and white pixels cannot be modified during compositing.
STEP 30: Lighting environment
Back in 3ds Max, I place the car into a basic studio scene setup with two area lights and a direction light. It's really easy to create. First, create a simple plane object, then make a few edge extrudes and chamfer those edges. My plane shape now looks like the backdrop of a basic photo studio. I create two pairs of area lights, which will create the highlights/edge lights and help to characterize the shape of my car. I also need a key light to give the main car a realistic look. Drop shadows and ambient effects are always needed when presenting our stuff.
Change the intensity of the lights until you feel they're good enough, and increase the light's shadow mapping sample size to get a smoother, cleaner shadow effect. The curved plane object now closes the area light's rays into a scene, all of them moving around the car. This helps to create a global illumination (GI) effect. Make sure the plane's Cast Shadows parameter is unchecked (Right click > Object Properties), because this object should not cast shadows over the car.
Now the studio scene is set up and working correctly. Finally, I create a simple Target Camera object, mark the target into the center of the car, move the camera around to find a good angle, and render!
I hope you have enjoyed this short post-apocalyptic car tutorial, and hope you can successfully create your own car with it.
See Part 1 here.
This tutorial was featured in issues 116 and 117 of 3dcreative magazine. Check them out for Maya cars and more 3ds Max asset creation!
Check out another of Tamas' vehicle tutorials here.
Learn how Markus Lovadina painted the original concept art in issue 108 of 2dartist magazine.