Hi, I’ve asked this question in the past, but re-visitng it again: given the lack of core support in Array for glVertexAttribDivisor, does anyone have any recommendations for getting per-instance data working easily?
I should state that I’m aware of the ‘use a texture and gl_InstanceID to sample it in the vertex shader' solution to this, but I need to pass somewhat more data than will fit into a standard texture for each instance (3 floats and various 8-bit values I could encode into a 32-bit int). In the refactoring of osg::Geometry, the _DIVISOR_ arguments to Array binding were removed, since there was never any backend support, so the only option I am sure will work is a custom drawable, where I manually setup the arrays / VBOs, call glVertexAttribDivisor myself, and then call glDrawArraysInstanced myself. (I.e, bypass Array / PrimitiveSet / all the ArrayDispatcher machinery / Geometry:draw) That feels like a rather excessive amount of work to solve this. Can anyone suggest anything simpler? I am aware that floating-point-textures might work to store my per-instance data needs, but I don’t have a good feeling for the portability of floating-point textures (on desktop hardware), whereas glVertexAttribDivisor is supported everywhere I care about. Similarly I’d be fine with making a hacked-up subclass of osg::Geometry which lets me bypass the ArrayDispatchers and invoke glVertexAttribDivisor myself, but I don’t know if that has a chance of working. Kind regards, James _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
