Question

How can I copy a texture from GPU memory to the CPU in WebGL? I am updating the texture using texSubImage2D in runtime.

I would like to avoid:

• storing a copy of a texture on a canvas
• rendering to texture and call readPixels

Is there any other way?

Already read these (which are useful for textures that are not updated during execution):

• Accessing image/texture data (texels) on WebGL
• Can one easily create an HTML image element from a WebGL texture object?

Answer 1

There is no other way than to attach your texture to an FBO and perform a readPixels.