How to get vertex position after translate in shader?

[jayiscool]

I creat a plane in the scene and set it a material, in vertex program I set some translate to mesh position, but when I use getMeshInfo() only get the original vertex position, how could I get the translated position?

in VS : oPosition = mul(worldViewProj, position+ float4(0,z,0,0));

[areay]

So you want the vertex program to update your mesh? That's a bit unrealistic because you would need to go and retrieve this data from the GPU at the end of the frame resulting in an FPS-crushing slowdown.

If you want to update your mesh as a one-off then you can get access to its vertex data and run the same simulation/modifications as your VS does (but in C++) and then save that into said vertex data of the mesh. Getting the data from the GPU after running the vertex program is a bit of a dead end.

[jayiscool]

So you want the vertex program to update your mesh? That's a bit unrealistic because you would need to go and retrieve this data from the GPU at the end of the frame resulting in an FPS-crushing slowdown.

If you want to update your mesh as a one-off then you can get access to its vertex data and run the same simulation/modifications as your VS does (but in C++) and then save that into said vertex data of the mesh. Getting the data from the GPU after running the vertex program is a bit of a dead end.

Thank you for your advice! But if transliation in program, how to verification the result of cpu is equal to gpu.

[drwbns]

Interesting topic, is there no way to tell the mesh of a translation using a geometry shader? Maybe http://www.ogre3d.org/docs/api/html/cla ... uffer.html could help here?

[areay]

It's probably OK to do as a one-off, just not every frame.

[jayiscool]

Interesting topic, is there no way to tell the mesh of a translation using a geometry shader? Maybe http://www.ogre3d.org/docs/api/html/cla ... uffer.html could help here?

There is little examples about geometry shader, I have never use it. But the link here may couldn't do what I want.