Add tangent generation to stride dynamic mesh

[tobyk]

If you use a material with normal mapping (AKA bump mapping) the mesh needs to have tangent data otherwise it will be black.

As reported here .

VL.Alembic object black with normal texture

Using AlembicPlayback with a PBRMaterial (Metallic) does not work with normal maps. So assigning any normal map turns the object black. I thought it might be related to some export option, but nothing helped so far. @torinos: hope you can have a look, and thx for the contribution!

Stride has a built in tangent calculation, which it uses on primitive meshes.

Feature request is to add the same calculation as an option on DynamicMesh nodes
It’s not too complex, code looks like this

AddTangentToDynamicMesh.zip (3.5 MB)

Here’s a working patch demonstraton. Its a modification of the ‘dynamic model from noise’ helppatch with UV coordinates and the tangent fix.
Note that it references directly Stride.Graphics.dll
Includes textures for a test material for normal mapping

If it’s working it should look like this

Texture source https://freepbr.com/materials/orbed-plastic/

[tonfilm]

Yes, very good point. I’ve already added a few things regarding tangents for a project in this branch: GitHub - studiobruell/VL.StandardLibs at feature-merge-compiled

[tobyk]

Nice, hope to see it in the StandardLib soon.

In case any future VL.PolyTools user stumbles across this thread in future I added a hidden ‘Calculate Tangents’ option to the PolygonPlane and PolygonExtrude nodes. And new helppatches about the entire topic of texturing these 3D poly things.