I am curious how other people approach the subdivision workflow in Solaris or what sidefx thinks the workflow should look like.
There are other posts [www.sidefx.com] about this explaining the basics but it doesn't seem very user friendly and I ran into some issues.
Here's my very simple workflow:
- Create a model in maya. The model is made of many objects all of them with different subdivision settings. Some of the objects I just set the subdivision levels to 0 that way they won't get any subdivision at all.
- Export selected model with multiple objects as alembic file. In the export settings I include the attributes for subdivision levels and other settings I need. This creates primitive attributes for every individual object when importing into Houdini.
- Create a Component Builder Setup and load the alembic in as render geometry.
- Using the
Treat Polygons as Subdivision Surfaces
enables subdivision on the whole model.
Here are some issues I have with this workflow:
- To enable subdivision in the viewport I go to the
Display Options
under Geometry and set the Level of Detail to 2. I then have to switch to Karma and back to get it to work. This is not documented in the docs. - This will show a preview of the geometry in the viewport in Houdini GL but this won't recalculate the normals. (If I enable subd in Maya, I get something that is equivalent of a subdivision node with a normal node. In the HoudiniGL viewport I get something that looks like the subdivision node, but without the normal node after.)
- Now we have a subdivided surface in Karma, except that it has all the tiny slivers of holes in the mesh between the faces. Let's come back to that later.
- Once I have the mesh subdivided in Karma, and I change a setting in my material Karma recalculates the whole subdivision geometry again.
- To speed this I try to lower the quality but I don't know how to control this at all. Can I control the quality per mesh? I have the subdivision levels per mesh from Maya, can I somehow use those levels to control the quality in Houdini?
- To set a mesh to render as subdivision one can use the checkbox on the import, but this doesn't give you any other settings. So there is the mesh_edit node with more settings. But to adjust the quality, I then have to use a third different node, the render geometry node where I can control how much subdivision is used with a setting that has a completely different name "dicing" and a parameter that has no explanation at all.
- To make lookdev possible, I tried to lower the subd quality. But lowering the quality across the whole object (since we can't control individual meshes) now brings back even bigger holes between the faces.
- I did end up downloading the ALab [animallogic.com] to take a look at their setup and they do use subdivision surfaces. For production renders, are we just supposed to crank this dicing quality until the holes disappear?
- Even if I split up my model into all the individual meshes, how do I set the settings on the mesh_edit node based on attributes in my alembic?
All this being said, I'm really just wondering, what is the proper workflow for this basic subd setup?
Are all the issues I'm running into just bugs, or are they only happening to me?
Are the points I raised not issues in other people's eyes?
Thanks,
Beat