Thread: Vertex Buffer Object - OpenGL

Hello!

So voila, I'd have `some question concerning the use of OpenGL VBO:
I have loader and view millions of points and perform processing on them (delaine etc ...)

currently j `VBO uses two: One for the coordinates and the second for the colors.

- Would it be more effective advocates use `n` that one and the same for both VBO information?

- What is the best technique to update the information?

(In the tutorials, the information’s are always handled by the CPU and everything is copied each time the corresponding VBO ... This method seems very bad, while the first because it did have a copy millions of points in the VRAM and RAM and then transfers because every time millions of points is very greedy. short interest no longer of use VBOs.)

In this case, how do the treatment directly on the VRAM or GPU?

Shaders or Not?

If I had used each time all of my points,` Is he still an advantage to use the VBI?

Thank you.

I tend to think it is better to pack a vertex position + color. After that it should see the alignment if the GPU like it or not. He must also see how you can reach: If you make multiple passes using just the position, and a final pass using color, finally this is the kind of compromise for a modern renderer. If you do just that plot points.

For the update, if all the VBO is changed, so it is better to copy it entirely. After that if you make partial changes, there's achtuche possible.

The VBI, IndexBuffer only of interest if they can effectively use the cache Post T & L (finally Vertexshader).

So if you have a VBO of colored dots, if just for a IndexBuffer makes wind, it is useless.

He must also see how you can reach: If you make multiple passes using just the position, and a final pass using color, finally this is the kind of compromise for a modern renderer.

Indeed, I proceed in this manner. In this case, I do work with my CPU and keep a copy of data in RAM. I do not know how he `d be interesting to use shaders to work directly in VBOs to computational, I'm (not really rendering)?

Ok i then as I thought the VBI `n` d have no interest in my case.

I thank you greatly.