Before you start texturing, it is very important to prepare for the texturing process. Preparing beforehand can allow us to use procedural techniques so we can have a solid base a lot quicker. the things that we need to prepare are:
• Mesh Maps
• Texture Reference
In order to texture quickly and efficiently, it is important to have UVs that will help the texturing process. I find that when I receive an asset, I have to UV it to my workflow so I can be more efficient with my time. This is usually how I lay out my UVs. Each row is a different part of the capsule meaning I can quickly identify which UDIM tile I need.
You can see in the bottom row, I have all the panels rotated at different angles. The reason I did this is so we can get per panel variation. Usually this would be quite destructive as we could have and overall coat without multiple seams, but as we are using Mari, we can use the triplanar mapping which means we can have the best of both worlds.
Panels at different angles for variation
Another important step to my workflow is having the correct mesh maps. The mesh maps I find myself needed the most are AO, Curvature, Normals and position. These can be baked out in a number of software’s for example xNormal and using the Modo Baking engine you can bake out Curvature and AO inside of Mari or Substance.
The next step is collecting texture Reference, for my asset, I was able to find a ton of high quality reference on the NASA website which made my life very easy. I used a great free application called PureRef in order to compile all the images in one place so that I could easily view all my reference while texturing.
For this project, I was using the ACES colour management system. In this case, we will be exporting all our textures as ACEScg. Selecting the ACES config in the colour setting works great but you can also path to a more recent version of ACES using the Custom OCIO Config box. If you are having trouble with ACES, I have a tutorial on how to set up ACES for Mari and Nuke as well as other on my YouTube channel. https://www.youtube.com/watch?v=ctCL0OhCGjk&t=467s
Now we have all of our maps we can start the texturing process. I tend to start my textures off with a base colour which I picked from my reference image. Next I have overlaid a tillable texture in order to cause some nice breakup across the surface. I then repeated the same technique a few more times using different maps and multiplying and screening them over.
Next I started building up some procedural build up in the crevasses by multiplying tillable over the AO bake. This creates some really nice and easy procedural breakup which we can then multiply over the base we already have.
This is the result:
We are already ready starting to build up some nicedetail into the mesh and we can continue this same process with the different bakes eg. Curvature, Normals and position to build up even more variation fully procedurally.
Left is after curvature and right is after normal using the same process explained above.
Now we have a good base, its time to start painting. Using the project through tool, I added on more and more detail with textures and I also started projecting on more details like the decals. After the decals were projected, I overlaid more textures to break up the text as well as hand painted some damage
In order to break up the American flag and for continuity, I used the same break up mask from the AO bake to influence the damage and then adjusted it slightly. Once the flag is multiplied by the mask, this is the result we get which has a similar look to the reference.
Left is before AO damage mask, right is after AO damage Mask
After an additional layer of hand painted breakup and the decals applied then an additional layer of dust applied, this is the result I got. This is the result I got. This brings us to the end of the creation of the diffuse map so we can now move onto the creation of the scalar maps such as metalness, roughness and bump.
Now we are done with the diffuse, we can right click on the last node and go to the edit menu, next we can select bake to paint node so that we can use our diffuse to inform our maps. Baking to paint node allows us to use a wide range of filter in Mari too such as blurs and high pass filters so we can push our maps further.
First of all I am going to make the bump map by desaturating the paint node then putting it through a high pass filter. This map will give us some really nice break up around the edges as well as bump the decals out so it looks like they have been painted over the metal.
The next map I will be creating is the metalness map. I created the metalness map by inverting the diffuse map so the paint and dust layers will be black (non-metal) and the metallic area will be white (metal). In this case just inverting then contrasting works but in most cases you will have to use the masks created when making the diffuse map to influence what areas are more metallic.
To create the roughness map I desaturated and contrasted the diffuse map. Luckily this was all I had to do as the roughest areas are the decal which is paint and the dust. Once again, most examples aren’t this easy and you will have to use the masks created for the diffuse to influence the roughness.
And that's it! We have now created the textures we needed to start doing the look dev in our render engine!