Procedural flat shading

Development Rendering
, , , ,
1

I would like to get advice/ opinions regarding stylized flat shading material for flat surfaces. It will be used on modular flat wall/flooring/ceiling kits.
My aim is to make a flat plane with texture applied to it look like a typical low poly flat shaded asset, with well defined triangles visible.

This set of constraints should be adhered to:

  • -Triangles should somewhat follow the actual texture, not just randomly
    placed.
  • -Triangles must be actual geometry. Normals alone are not enough.
  • -No anything above of what material editor/blueprints can offer.
  • -Avoid repetition when modular pieces are placed into the game level.

So far I’ve identified three possible paths for me to follow:

  1. Procedural mesh generation in
    blueprints, based of height map and
    noise.
  2. Use of tessellation shader.
    Something like tessellation
    multiplier map, that controls the
    size of triangles, height map for
    displacement, and random noise to
    offset the vertices, coupled with
    reconstructing new normals after
    that. I’m frankly favoring this
    option so far as I’ve successfully
    used it before, but I have concerns,
    mostly because whole scene is likely
    to be always transform bottlenecked.
  3. Instead of doing it in the engine,
    automate the process in content
    creation software, and export
    several variations of the same mesh.

Maybe anyone has something to say regarding that? My in advance.

2

If I am understanding you correctly I would create a tileable normal map based off a triangulated mesh like this

109702-lowpoly_n.jpg
109702-lowpoly_n.jpg1024×1024 128 KB

.

Granted I would make it more random and less grid like, but this image is just an example. I don’t think tessellation is needed if you use a plane with enough triangles already in it. You would save on performance rather than actively tessellating though the shader. You can still use your height map and noise idea, but just world position offset should suffice.

Also make sure the plane has no smoothing groups and the mesh is set to compute normals.

Thats my opinion anyway,

3

Hi, I am currently struggling with the same problem. Right now what I have is a procedurally created mesh that is unfortunately way too smooth. How did you approach the wanted result? I see the answer below was accepted but I’d be incredibly grateful if you showed your method in more detail. in advance!

260644-screenshot-4.png
260644-screenshot-4.png830×606 564 KB

4

Jeez, that was two years ago. I’ve ended up following advice by and using procedurally generated normal map and displacement map, based on several octaves of Voronoi noise.

5

Oh, and you still remember :slight_smile: Thank you, it’s a big help. One more little question: did you manage to get the collision working? Or maybe you didn’t even need the collision?

6

The scope did not involve collision. I only needed flat shaded appearance on models, that were not authored with flat shading in mind.