I'm creating a livery for a car model, and I want to do this in 3D using Blender. I have the mesh loaded into a Blender file, and I can paint on it fine.
Once I have defined a base livery, I create another image to use as a "decals" layer. This layer should contains logos, numbers, names and all the other stuff you usually see on race cars. Currently, I simply draw them on the "decals" image, and I use 3D objects as a reference for the position of the stencil (place a cube, scale it so it matches the aspect ratio of the image, place it so that a face of it shows where the stencil should be placed), but then I have to manually place the stencil, and to do it again on the other side.
While this is enough for the image resolution I need, it is still time consuming and makes it hard to "just try" and experiment.
I thought about making my decals using actual 3D objects, texturing those with the decal images and baking them into the result, but I can't change the UV mapping of the car mesh, and matching the UV mapping of the decal objects with the UV mapping of the car object would kinda defeat the point of painting the livery in 3D.
Is there a better way?
This is what I use now: The grey blocks' small sides represent a decal. If I go into orthogonal side view, I can manually line up the stencil and paint on the car. Once I paint, if I wanted to move it or resize it I'd have to erase it and paint it again.
Ideally, I'd like a way to "project" the plane's texture onto the car's texture, but in a non destructive way, so that I can move the plane around or resize it and "regenerate" the car's texture.
AFAIK, in order to bake I'd need to join the meshes and re-UV-map the joined mesh, but I can't alter the car's UV (it's an asset of a game), and I don't know how to "burn" the plane's texture on the car's texture in a different way.