topic Re: Alembic export Triangulation in 3ds Max Forum

Alembic export Triangulation

Anonymous — Sun, 23 Jul 2017 21:02:13 GMT

Is there a way to stop the triangulation of geometry when exporting as alembic file? Both 2016 and 2017 versions always do this, haven't tried 2018. Would like to keep model as quads. All versions of Maya don't triangulate when exporting.

Re: Alembic export Triangulation

Anonymous — Sun, 23 Jul 2017 22:22:11 GMT

May have figured it out myself. Apparently there are hidden edges. Adding a polyselect modifier keeps it quad. If anyone can elaborate, that'll be great.

Re: Alembic export Triangulation

Alfred.DeFlaminis — Wed, 09 Aug 2017 22:52:40 GMT

Hello @Anonymous,

First, I'd like to apologize that you experienced such a long delay before you got a reply here. I'd like to help find an answer for you. Are you still having this issue? I've tested in 2016, 2017, and 2018... always appear as quads when I re-import. I'm using the "Ogawa" file format.

I wonder if one of the modifiers on your stack is causing this. When I export as a simple Editable Poly it comes back that same way. Thanks for any extra details you can give me to help repro this.

Best Regards,

Re: Alembic export Triangulation

PiXeL_MoNKeY — Wed, 09 Aug 2017 23:39:03 GMT

@Anonymous wrote:

May have figured it out myself. Apparently there are hidden edges. Adding a polyselect modifier keeps it quad. If anyone can elaborate, that'll be great.

This is a difference in the classes. A mesh object is stored and exported as a Trimesh class. A trimesh consists of a face defined by 3 vertices. An editable mesh has hidden edges which hides the edges, but doesn't remove them. A poly object is a completely different class of object in 3ds max. A face in a poly object is defined by 3 or more vertices. Using any poly modifier converts the incoming modifier stack data to a poly object class and converts vertices at visible edge corners to to the poly face vertices.

Hope that helps a little in why the difference.

-Eric

Re: Alembic export Triangulation

Alfred.DeFlaminis — Wed, 09 Aug 2017 23:43:32 GMT

Very good post @PiXeL_MoNKeY and excellent point. I work so much with Edit Poly I didn't consider the Edit Mesh. Good man. I have to agree with Eric here, most likely these were mesh objects on export and putting that PolySelect on top must be also converting to poly. I always thought you needed a "Turn to Poly" mod under it to do that but perhaps not.

Best Regards,

Re: Alembic export Triangulation

PiXeL_MoNKeY — Thu, 10 Aug 2017 00:15:44 GMT

The "Turn to" modifiers are lower overhead modifiers as they remove the selection and modification features making them quicker to process. They also provide options that the selection mods, edit mods, and convert to commands don't have like defining how edges are converted from one class to another.

For example, the Turn to Poly modifier allows you to define the maximum number of edges per face. It won't create new edges, but will define if invisible edges need to be converted to Poly face edges.

-Eric

Re: Alembic export Triangulation

Alfred.DeFlaminis — Thu, 10 Aug 2017 22:11:27 GMT

Excellent write up @PiXeL_MoNKeY, good information. Kudos.

Best Regards,

Re: Alembic export Triangulation

Alfred.DeFlaminis — Thu, 10 Aug 2017 22:11:51 GMT

Hello @Anonymous,

I just wanted to follow up here, any progress on this issue?

Best Regards,