Vbo transformations

Hi , im very new to LWJGL and using VBOS and I am wandering how to manipulate VBOS without methods such as glRotate. Do I need to use shaders and Matrixis?

Yes that’s exactly what you’ll need. I personally don’t know of any matrix libraries for LWJGL, but to be honest, matrices aren’t that bad once you get them down, and using them in your shaders are even easier. The hardest one of them all is that damn rotation matrix, but the rest are very easy. If you haven’t, read up a little on matrices, and suddenly everything will make much more sense.

Besides the damn rotation matrix.

My suggestion for reading material on transformation matrices: http://www.wildbunny.co.uk/blog/vector-maths-a-primer-for-games-programmers/. And LWJGL has its own Vector and Matrix classes that should be sufficient for anything you need to do.

@opiop65 Rotation matrices aren’t so hard if you think about them in the right way. I think of 3x3 matrices as defining a set of axes. The first row the x axis, the second the y and the third the z. So with the identity matrix:

1 0 0 X axis
0 1 0 Y axis
0 0 1 Z axis

Then a rotation (about a single axis) is a simple matter of trig. But the beauty of matrices is that a complex transformation is only as complex as its individual components. I won’t bore/patronize you by talking through the maths but I feel like it’s a good way to think about it. Just (what I think is) a handy hint.

Thanks! My main issue was figuring out the trig behind it. I’m currently in trig, so when so was trying to figure out the rotation matrix a couple months ago I was struggling with the math, that’s the only reason I “hate” it! :slight_smile:

The only time I ever enjoy trig is when its correct in a test :), Never liked circles and never will!