Tessellation Shaders for OSG Terrain

[drabeiter]

Hello everyone!

Sorry if this ends up being trivial, but I'm pretty new to OSG and GLSL. I'm trying to add tessellation shaders to an osgTerrain::Terrain, and to keep things simple, I'm just passing through the tessellation shaders for now. But I'm running into "invalid operation" errors, and I think it may have to do with setting the primitive to patches. Has someone run into this issue before, or do you have any hints to solve this?

Thanks!

Andy