Vertex transform and readback

Hi all,

I want to know how I can perform vertex transformation and readback result.

(I know I can copy vertex attributes into a texture, transform them by a pixel shader and readback the result via a render to texture)

But doesn’t it have a best solution like :

1 -Draw normally polygon …

2- Set a vertex transformation shader,

3- Read back the result into CPU memory.

Thanks in advance :smiley:

If you have a shader model 4.0 NVIDIA card, you can use the transform feedback extension to render from the vertex shader or geometry shader into a VBO.