Forums Technical Discussion True Displacement parameter?

True Displacement parameter?

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Felix6699
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Hello experts Houdini!

Get to the point. The attached video you can see the artifact. It occurs when the TRUE Displacements is enabled and the camera is close to the object. I want to know is why is this happening? In my scene: plane NURBS, shader basic liquid, camera, light source Point, animated displacement map and nothing more.

Thanks in advance for your reply.

Attachments:
what_with_disp.avi (465.7 KB)
problem_disp_00!!88.jpg (36.8 KB)

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Erik_JE
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Check the near clipping plane for your camera.
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Felix6699
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Erik_JE
Check the near clipping plane for your camera.

Thank you for your response, Erik_JE. But if be it solved the problem … The task is to use the displacement (true displacement) and fly low above the waves. Then the camera dives into the ocean. The “Near Clipping” option in the camera does not solve the problem (I assigned it in 0.0000000000000001 :?). For example, the other programs 3D graphics such problems are I not found. And do I need this effect in Houdini.
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rafaels
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Can you reproduce the problem in a simple scene setup that you'd be wiling to share?
If the “true displacement” is displacing along the normals, I'd suspect the normals on the edge of that plane are not correct… but I'm not sure.

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Felix6699
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rafaels
Can you reproduce the problem in a simple scene setup that you'd be wiling to share?
If the “true displacement” is displacing along the normals, I'd suspect the normals on the edge of that plane are not correct… but I'm not sure.
Cheers

Rafaels, maybe… Anyway, I reproduced this moment. When the camera intersects the plane appear ragged artifacts. I would like to get rid of them and instead of it were straight edges (at least).

Attachments:
archive_hip.ZIP (2.6 MB)

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rafaels
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Might be something related to the tesselation on your nurbs plane.
I converted it to polygons and it now works fine here. Is that an option for you?

Cheers
Toronto - ON
My Houdini playground [renderfarm.tumblr.com]
“As technology advances, the rendering time remains constant.”
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Felix6699
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rafaels
Might be something related to the tesselation on your nurbs plane.
I converted it to polygons and it now works fine here. Is that an option for you?
Cheers

Oops . That's it also happens. Option to look into the “Primitive Type” - it's cool. I was not thinking about it.. And it work! Though with some reservations. The “Micropolygon render” - crash :?, but “Ray Tracing” it works stable and in one frame shot a few bugs in image. Your option is suitable and I will continue to work over the idea. Thank you for your responsiveness and help.
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