OTOY Forums

Can anyone tell me how to use this? I have two image textures that will define two different areas of displacement with different displacement heights. I want to use the displacement mixer node but Octane crashes every time I try to use it.

What's the correct procedure?

It's vertex displacement mixer. I didn't give full name because to save space in gui. Looks like that was not a good decision. BTW how can you make it crashed?

so it does not work with image maps?

don't know how I crashed it, just connecting nodes

Vertex displacement refers to the type of displacement used, not the type of map that is creating the displacement. You are free to use image maps and procedurals with vertex displacement.

The Displacement mixer is limited to Vertex displacement only. You cannot mix texture displacement and vertex displacement in the Displacement mixer.

Thanks, can you explain the difference between ordinary displacement and vector displacement?

Is there a tutorial about this stuff anywhere?

simply put, texture displacement is unidirectional on the normal or vertical. It uses grayscale maps to determine the ratio of displacement and the height value to scale within that ratio. Vertex displacement is omni-directional. It can use either grayscale maps or vector maps (RGB colors, with each component representing an axis of displacement -- RGB to XYZ), much in the same way that a normal map fakes shading, except with real geometry. One of the benefits of using vector maps for displacement is that undercuts are enabled, so you can do things like taking a Zbrush vector map and get the same result in Octane, which is pretty cool. You do need to have an appropriate amount of tessellation, which is one of the downsides of vertex displacement when compared to texture displacement. It will cost more memory and take longer to generate.

Displacement needs memory in general, also working with Texture Displacement, with 8k 32bit textures, takes a lot of VRAM, and you don’t need such resolution with Vertex Displacement to obtain good results, and using procedural textures saves a lot of VRAM.
But another thing to consider is that new Vertex Displacement can be accelerated by RTX, while the old Texture Displacement cannot, since it is not based on polygons.
ciao Beppe