Displacement not displacing on Polysurface

Rendering
1

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image1459Ă—686 261 KB

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image461Ă—669 14.5 KB

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image964Ă—654 71 KB

I wish to displace some of the surfaces of this shoe using the displacement modifier but oddly it does not displace anything.
I have done this before and never ran into an issue.

Displacement does work if I seperate the surface as visible in image 3.

No errors.

What am I missing?

2

Hi Yannic,

A bit out of my arena but I was able to gather some good info..

Things to check / try:

  1. Sub-object select the face first — Hold Ctrl+Shift and click the specific face to sub-object select it, then apply the displacement. Don’t select the whole polysurface at the object level.
  2. Check the “On” toggle per face — In the Displacement properties panel, when a sub-object face is selected, verify the On checkbox is checked. This setting is per-face for polysurfaces.
  3. Texture mapping — Make sure a texture mapping channel is assigned. Without valid UV mapping on the face, the displacement texture has nothing to sample from.
  4. Mesh density — Low initial mesh settings can cause displacement to appear flat. Increase the mesh quality under Properties > Mesh or the displacement mesh settings.
  5. Extract the face, displace, then rejoin — As a workaround (since it works on the extracted surface), you can ExtractSrf, apply displacement, and use Join — though note the displaced mesh won’t rejoin as a watertight solid; it’s a render-time effect.

If the issue persists, sharing the .3dm file may be required.

3

Hi Japhy,

Thank you for your awesome quick reply. I’ve tried the methods you outlined. But either I am missing something or It changed nothing.

Download from my drive (since its too big)

It would be awesome if we could figure this out. I received this file from a third party and I believe their tolerances may have been greater than mine.

Ps: I require a watertight mesh.

4

Do you know when this last worked for you? What is your current Rhino version (please run SystemInfo in the command line)

Thanks, we’ll take a look.

5

I have evidence, that I was able to do this on 2026.02.11 but an earlier version of the file.

My testing:

(I used import to import these models into the same file and then tried displacement on the same surface of each)

Yeah, so odd situation.

Sysinfo below:
2026.02.22 Sysinfo.txt (2.2 KB)

Thank you again!

6

Hello,

it’s basically a displacement bug in Rhino that’s been around for a few years. I found a kind of custom workaround: you extract the surface and then hit Ctrl+Z. After doing that, the displacement will show up again, but probably on the wrong faces, so you’ll need to reapply it to the desired face.

Let me know!

7

Hi @Yannic_Noack ,

I believe the issue here is some trimmed edges in the polysrf. Extraction of the surfaces allows displacement but not when it is joined. I would recommend lowering the settings too. I generally don’t go higher than Very High and adjust the objects render mesh instead.

I filed a new bug report too with a few srfs from your model so that this can get looked at by development. https://mcneel.myjetbrains.com/youtrack/issue/RH-92692 Thank you.

8

Hi @BrianJ and @A2RC ,

I found a workaround that allows me to apply subobject displacement.

Workaround:

  1. Export as STEP using AP242 (also works with AP203)

  2. in a new file, import that step

    image
    image392Ă—284 9.07 KB

  3. apply subobject displacement

Further Bugs with above workaround

  • If the STEP is imported more than once, only the first one will allow displacement, regardless of the settings used.
9

Sadly did not work for me :frowning: