How to create a FBO with stencil buffer in OpenGL ES 2.0?

Question

I need stencil buffer on 3GS to render planar shadow, and polygon offset won\'t work prefect, still has z-fighting problem. So I use stencil buffer to make the shadow correc

Answer 1

In OpenGL ES 2.0 on iOS, you have to create a combined depth and stencil renderbuffer using GL_DEPTH24_STENCIL8_OES, and then attach it to the bound framebuffer as both GL_DEPTH_ATTACHMENT and GL_STENCIL_ATTACHMENT.

glGenRenderbuffers(1, &depthStencilRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, depthStencilRenderbuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthStencilRenderbuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthStencilRenderbuffer);

Answer 2

Just a note, if you are using GLKView, it is as simple as

view.drawableStencilFormat = GLKViewDrawableStencilFormat8;

where view is: GLKView*