I’m having trouble starting out this program that deals with transformations. Even though opengl is able to do transformations for you, I am required to do this by developing another class and “manually” computing the transformations within my application. I have no idea where to start or even how to do this. I was wondering if somebody could point me in the right direction (Not give me the answer) and help get me started with this. :eek:

Maybe looking at the Redbook Appendix: Homogeneous Cooridinates and Transformation Matrices will give you an idea of how to start. Some other sites worth looking at are OpenGL Transformations or openGL Maths. These show you the math behind what openGL is doing.

Basically, you need to generate 4x4 matrices for each of the operations; translate, scale, lookat, perspective, etc. And simply multiply them successively (just as openGL<3 does for you) to build a final 4x4 matrix that represents your desired transformation. There is no reason you couldn’t build your own code that does the same math.

After you understand the transforms marshats pointed you to, you’ll need plug-and-play code base to start from, unless you want to retype it all manually. Many maths-libs exist, among them the best probably are nv_math (from nvidia SDK) and GLM (GL-maths).

I’m using a modified and extended nv_math like this:

http://dl.getdropbox.com/u/1969613/openglForum/ILXMath.h

http://dl.getdropbox.com/u/1969613/openglForum/ILXMath.cpp

Thanks!

I understand the transformations more clearly.

Ilian Dinev, is there a plug and play code for java. I searched but was unsuccessful in finding one.

I don’t know, I use Java only for mobiles and there I port the few C++ func I need.