I'm pretty sure that I have the code setup properly to do this. My graphics card supports openGL 4.0, but I'm still using a GL 2.0 context.

Can I still use the extension? My code compiles and glew seems to find the extension pointer. I assume because it doesn't crash that everything is good and I just have to debug this but I wanted to make sure.

I got it working now. I forgot with this mesh I was using is using non-indexed and needed to use glDrawArraysInstanced instead of glDrawElementsInstanced

My new problem is this. The second I add in all this per-instance attributes along with glDrawArraysInstanced, nothing show up. My shader works when I draw with glDrawArrays so the shader is perfectly fine. glDrawArraysInstanced is working, but just when I turn on the surrounding attribute code which is to pass an instance color down, nothing show. I don't know if its somehow over-writing other attributes or if I have messed up badly.

I can say that a don't use vertex attributes for the rest of the data. I use multi-texture coords for tangents and other per vertex data at the moment. Is this my problem that I'm using gl_Vertex and the built-in attributes along with my own custom ones? attribLoc seems to = 4 and be valid tho.

int attribLoc = glGetAttribLocation(NormalMap.handle_, "color");
glEnableVertexAttribArray(attribLoc);
glBindBuffer(GL_ARRAY_BUFFER, VBO_Index);
glVertexAttribPointer(attribLoc, 4, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 4, (void*)(0));
glVertexAttribDivisor(attribLoc, 2);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

glDrawArraysInstanced(GL_TRIANGLES, 0, meshToRender->num_faces*3, 2);


glDisableVertexAttribArray(attribLoc);

That's correct, I tried using per instance and per 2 instances, but at the end of the day that attribute is a color to the shaders, nothing to do with position. So I should at least see something rendered. Like I do without using the per-instance attributes.

ARB didnt do anything, I don't use ARB in anything, I think glew strips that by default. Either way it worked just not with the attributes turned on, hopefully this doesn't turn into a long bug.

I'll give that a try. Well it does return 4 as a valid index, and i have pos,normal,texcoord,tangent so the next attribute would be 4.

I would think it still knows though because my shader compiles knowing what built-in and custom attributes to use an build an index map for them. I still call glVertexPointer, normal texcoord, which those might map to a default.

I get what you are saying though it probably is the issue, don't know what else it would be.

So yes, you can use mixed attributes. My prior glVertex,glNormal,glTexCoord pointers all still work with adding another attribute I have create.

My issue was my new vbo to hold matrices was bad. I forgot to call glBufferData() before calling glBufferSubData(), so it was all garbage.