Displacement breaks point/vertex attributes

[mlmcgoogan]

Plugin version: 2019.1.4 (11/22/19) (Enteprise sub)
HDK Version: 18.0.287.9


Attached is a simple example HIP. Basically any displacement fed into a material node breaks any point attributes used in the material. Using a procedural texture in the HIP but this happens with loaded textures as well. If you disconnect the displacement, the point attribute will read correctly, with displacement connected, point attributes no longer work.

I'm not sure if this is an existing limitation or a new bug but this kills a lot of my workflow if I cant get displacement alongside point attribs. I've been shifting back to Octane from Redshift because of the improved network rendering but this has been causing a number of blocker issues for me.

Thanks for any assist juanjgon!

[blobbybarack]

Not in front of a computer but i m curious.
With and without subdivision at the new displace node?

[mlmcgoogan]

The new Vertex Displacement node does not break attributes. Unfortunately for typical float texture displacement, the Vertex Displacement node is about an order of magnitude slower to achieve similar results.

[juanjgon]

Yes, sorry, this is a known limitation of the conventional old displacement node, although I think that this is a planned feature in the short term.

Meanwhile, the solution is to use the new vertex displacement node, that doesn't have this limitation.

Thanks,
-Juanjo

[mlmcgoogan]

Understood, thanks for the update!

[mlmcgoogan]

juanjgon,

Out of curiosity, what's the difference in terms of how the regular Displacement node works vs. vertex displacement? It seems like Vertex Displacement is just doing render-time tessellation and interpolating attrib values? How does the regular Displacement node work differently?

[blobbybarack]

You could use procedural with the new one abnd as far i remenber you can't set up subdiv level at shader level with the older

[juanjgon]

The vertex displacement works like the conventional tessellation and displacement features found in near all other CPU and GPU renderers, computing a physically subdivided/displaced mesh before rendering the scene. The old Octane displacement node works at render time, without physically subdivide or displace the base mesh.

Thanks,
-Juanjo