I am trying to write a plugin for Unity that does the following on iOS using OpenGL ES 2.0:
The plugin is called in the update function of a script attached to the main camera.
The sticking point comes when I try and draw the textured quad in the offscreen FBO with
This is the complete draw function:
The fragment and vertex programs are just simple pass throughs:
I took my plugin code and implemented it as a stand alone app, doing the same thing, and everything worked.
Does anyone have any idea what is wrong?
I think there are 2 things going on that are making that function not work.
First is that Unity uses VBO's on android, and it's leaving a VBO bound when you are calling your function. So when you are making the "glVertexAttribPointer" call, it's interpreting your "textureVertices" pointer as an offset into the bound VBO. See the glVertexAttribPointer docs here for more info on that: http://www.khronos.org/opengles/sdk/docs/man/xhtml/glVertexAttribPointer.xml
So you need to unbind Unity's VBO with a call to glBindBuffer with a buffer handle of 0, so like this:
The other problem I think you are having is that you are trying to use the existing program handle when rendering the quad. I don't know what code you did in Unity land to try and set the current program before calling your native function, but when I've played around with this stuff, I was using material.SetPass(0), and that function was not setting the current program :(
The only way I could get stuff to render in a native plugin for android was to use a program created in the plugin itself, as Unity wasn't "glUseProgram"ing for me :P
answered Aug 07 '12 at 04:47 PM