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Bug with Alembic and SubD

Posted: Mon Jun 16, 2014 8:13 am
by Rikk The Gaijin
I found a weird problem when trying to subdivide an alembic file with a sss material.
01.jpg
The image above is the scene without any subdivision.
The image below is with one level of subdivision. As you can see the shader changes completely and the material becomes gray! :?
02.jpg
It happens only with alembic. I tried the same scene as OBJ and the subdivision worked fine with no side effects on the material.
Any idea? :?

Re: Bug with Alembic and SubD

Posted: Tue Jun 17, 2014 12:51 am
by Rikk The Gaijin
No replies?! :o
I can send the scene if needed!

Re: Bug with Alembic and SubD

Posted: Thu Jun 19, 2014 12:30 am
by Rikk The Gaijin
Image

Re: Bug with Alembic and SubD

Posted: Thu Jun 19, 2014 12:36 am
by roeland
Can you post a render of the interpolated shading normals output of the info channels kernel, without and with subdivision?

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Roeland

Re: Bug with Alembic and SubD

Posted: Thu Jun 19, 2014 12:47 am
by Rikk The Gaijin
roeland wrote:Can you post a render of the interpolated shading normals output of the info channels kernel, without and with subdivision?
Super-Roeland as usual knows his stuff... 8-)
The render of the normal does indeed get fucked up with the subdiv ON.
bug.jpg

Re: Bug with Alembic and SubD

Posted: Fri Jun 20, 2014 12:02 am
by roeland
The normals are flipped when subD is enabled, but I can't reproduce this issue here. What are the other settings under the common import preferences?

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Roeland

Re: Bug with Alembic and SubD

Posted: Mon Jun 23, 2014 12:42 am
by Rikk The Gaijin
roeland wrote:The normals are flipped when subD is enabled, but I can't reproduce this issue here. What are the other settings under the common import preferences?

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Roeland
Those are default settings, I haven't touch them. At this point it's easier if you try the scene yourself, I send you a PM ;)

Re: Bug with Alembic and SubD

Posted: Mon Jun 23, 2014 12:51 am
by roeland
OK thanks, I will have a look.

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Roeland

Re: Bug with Alembic and SubD

Posted: Mon Jun 23, 2014 3:19 am
by roeland
The mask is exported using clockwise winding order, so in the geometry import preferences for the alembic file you need to enable "flip face normals".

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Roeland

Re: Bug with Alembic and SubD

Posted: Tue Jun 24, 2014 1:17 am
by Rikk The Gaijin
roeland wrote:The mask is exported using clockwise winding order, so in the geometry import preferences for the alembic file you need to enable "flip face normals".

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Roeland
Thank you Roeland, but why does it happens? Is it a bug in the Maya Alembic exporter? It doesn't happen with OBJ. :?