Negatives clipping with 32 bit displacement

[Aerys]

Hello, I'm testing the Octane for Houdini demo and finding myself unable to render a character model with displacement. It seems the negative values are clipped. I am using an ordinary zero centered 32bit exr exported from zbrush that works fine in other engines. Fiddling with settings on the image input and displacement nodes didn't seem to change anything.




I did also notice an old thread reporting the same negative displacement clipping issue. Here's a simple scene that shows the problem.
https://www.dropbox.com/s/3wf0olz44x3tn ... t.zip?dl=0

[bepeg4d]

Hi,
you need to use the new Vector Displacement node, instead of the old Texture Displacement node:

The Vector Displacement can be used with procedural textures, but also with image textures in Height mode.
Take a look at the difference in wireframe mode, the old displacement does not need subdivisions, but has some limitations, like negative values or tiling, while thenew displacement works with subdivisions, and does not have those limitations:

ciao Beppe

[Lewis]

But take notice that vector displacements eat VRAM like crazy and it's lot slower in some cases (when adding high subdivision needed for small details)

[Aerys]

Thank you for your help @bepeg4d and @Lewis. The Vector Displacement was something I tried but I figured I was not using the node correctly. It seems like Vertex Displacement is more sensitive to your texture's input gamma, which must be changed to 1.0 to work correctly. As far as I can tell the gamma setting on your texture node doesn't affect the old displacement. But it is working now!