Export custom normals to SMD

[Zyl]

Hello,

I have a plugin which edits normals all in an attempt to save polys, but Blender Source Tools appear to still use plain smoothed normals? Here is (roughly) what the plugin does (within an operator execute function definition):

me = context.object.data
bm = bmesh.new()
bm.from_mesh(me)
for v in bm.verts:
  v.normal = some_custom_normal
bm.to_mesh(me)

The change is visible in Blender and is preserved between saving and loading the .blend file. Only entering edit mode on the mesh resets the normals. Can I have it my way?

[Zappy]

I'm not sure if I understand you right, but the Blender Source Tools (by default) don't import SMD normals. But exporting them should be fine. Either way, I know for certain it works with DMX.

[Zyl]

I don't think I can use DMX for a Source SDK 2006 game. Is someone with extensive Blender Python API knowledge around who can shine some light on this?

[Zappy]

Again, it should EXPORT fine, just not IMPORT. Also, Half-Life 2 was released in 2004, and I'd be very surprised if it does not use DMX. At least try before saying it won't work.

[Zyl]

I am trying to export. Studiomdl says it "can't open file" when I use dmx. Now this may be because I don't know which "binary" and "model" target version to specify.

Anyway, I solved the problem. The source of the problem is the triangulation process: https://blender.stackexchange.com/questions/7033/how-can-i-triangulate-a-mesh-without-changing-the-object

I solved this by adding and applying a triangluation modifier myself, then applying my normal modification, and then writing my own SMD exporter which expects triangles. The custom normals don't get touched and everything is fine. People who want to use this technique should make sure to save backups of their .blend files without the triangulation modifier applied.

Here is the plugin I wrote: http://pastebin.com/0mfyv4yn

[Zappy]

You do know about the "Engine path" path, right? If set to a directory with StudioMDL, it should auto-detect which DMX version to use. Additionally, the QC itself might say ".smd".

[Zyl]

Setting engine path forces SMD being used for me. The DMX/SMD switch GUI element is omitted.

[Zappy]

Then it only supports SMD, it seems. Oh, well. At least you made something that works for you.

[Artfunkel]

Run the "Add Custom Split Normals Data" operator then edit the mesh's loop normals. That's the proper way of doing it and those normal data will be stored permanently in the blend, never to be recalculated.

I'm pretty sure they will survive export to SMD too, but triangulation may indeed be an issue. The custom normals system just doesn't support topological changes. :(