So currently I have an overlay VBO object and a world VBO object , overlay is rendered after the world and I would like the overlay object to blend with the world object based on the alpha value. I know this can be done with a single VBO but that would mean rewriting the majority of my VBO code.
If this is not even possible then please let me know.
it is possible, but i dont understand it yet.
VBO is “just” vertex data. so, in a two-pass rendering, with two projection matrices, 2nd pass not depth tested and different blending functions (using alpha) it is very possible.
if you mean FBO, then it’s just rendering into two textures. basically like the two-render pass above + another pass to blend the two FBO textures, maybe with a custom shader. actually you dont need any shaders for this.
o/