Stride: Geometry Instancing

[GutterLab]

Is your feature request related to a problem? Please describe.
Being able to draw a lot of the same thing while staying performant.

Describe the solution you'd like
Support for geometry instancing.

Additional context
https://en.wikipedia.org/wiki/Geometry_instancing

[tebjan]

as discussed with @xen2 this could be quickly done with stream out / transform feedback. it would avoid rewriting all shaders which would be a huge task. drawback is, not same performance as correct implementation in shaders but still some order of magnitude faster than multiple draw calls.

[xen2]

@tebjan Fine with doing that to start with.
I think the main other concern was how to gather instances (should we find duplicate draw call automatically or have an explicit way to describe those?)

[tebjan]

user controlled instancing at first was the conclusion. if you know a way to gather models by shader it could also be interesting....

[yangguosdxl]

Maybe automatically gather instances not very emergency。this can do by game logic. Generally, may be we just want a method to commit geometry instancing :-)

[Eideren]

Should we close this issue now that your PR is merged ? @tebjan

[tebjan]

Yes, indeed!