Title pretty much says it. Can't find a way to retain set hard edges from maya to houdini. Have tried obj, dxf. Is there any way of doing this?

Thanks,
Nic

This is because Houdini doesnt support vertex Normals while Maya does.

There is a Vertexsplit SOP that'll split points on your geometry in Houdini you specify that if it finds there is a difference in the vertex Normals exported from Maya.

Sorry I don't have time to write more, but investigate this approach. Its what we do and it works adequately for most tasks. Unfortunately this changes the geometry topology so you cannot send the geometry back to Maya and expect the same point count, etc.

Hope this helps,
Jason

yeah but that kind of defeats the purpose. particuliarly if there was a large scene with many hard edges throughout, you would have to go through and select every edge to apply to in houdini.

If there was a selection set of all hard edges would be nice, then you could just apply an EdgeCusp SOP to that group. Selection sets when exported out of Maya using “point groups” checked on the obj exporter, will show up in Houdini, but they come up as empty groups.

I've just realized that none of the standard exporters from Maya will export vertex Normals (although normals ARE available per vertex in Maya). Am I right, or is there an exporter that will do it?

We at DD have our own BGEO exporter Maya plugin which exports vertex Normals from Maya correctly and so in order to achieve the same cusping in Houdini we need to just use a VertexSplit SOP to do it. We do not split the points at the export stage and only use a VertexSplit if we are going to render from Houdini. Otherwise we can pass the geometry back to Maya and the cusping and topology is preserved. No need for cusping groups or anything, it's a fluid process; but we do wish Houdini supported vertex Normals.

Sorry for the confusion.

Yeah, I've long wished for an improvement in this area. When you have to unshare points, you get Displacement problems too, where things will split apart. Another vote for Vertex Normals in Houdini!

Cheers,

Peter B

hmh, have anyone tried Okino PolyTrans for exporting/importing stuff.
It supports houdini file format, so it may help…

pbowmar
Yeah, I've long wished for an improvement in this area. When you have to unshare points, you get Displacement problems too, where things will split apart. Another vote for Vertex Normals in Houdini!

It's been on our RFE list for a while but I suppose it might well be a task larger than we expect to support vertex normals throughout. My initial desire would be to have Mantra support it first, then the display and the SOPs in Houdini itself. This would seem a good way to approach it since just getting it into Mantra would probably raise a lot of issues on where the hotspots in Houdini were.

Cheers,
Jason

PS. For curiosity's sake, I'd also like to know if PolyTrans exports vertex normals.

well, someone can send me a problematic maya file, I'll do a conversion and send it back… and truth will be revealed 8)
djorzgulgmail.com
respect

djordje

argh…
no option to export to houdini .geo format, just import…
:?

Well the obj format does support vertex normals to a point(no pun intended ), they become the point normals in Houdini. Transfering them is not a problem as I have in Maya had models with seams. I have then manually set their vertex normals or by averaging the vertex normals at the seams. Bringing them into Houdini with the .obj works fine, vertex/point normals at the the seams stay intact.

Its just the way hard edges are handled. The hard edges are formed by spliting the vertex normals 90 degrees, giving multiple vertex normals, one for each edge going into a vertex. But the .obj format doesn't support multiple vertex normals.

As for using Polytrans or such, we don't have it available here at work, so I was trying to find a workaround. Instead having to set them all manually in Houdini.