function of Transfer3Dto2D

superpop · Post by **superpop** » Mon Jul 09, 2007 10:55 am

How to transfer 3D to 2d ,I want to define the function like
Transfer3Dto2D(float x[],float y[],float z[],int num,int zprp，CPoint& ptr2d[])
in opengl the function gluProject can realize the function.

i want to konw the detial of the realization of the funcion of gluProject.

hybrid · Post by **hybrid** » Mon Jul 09, 2007 1:00 pm

gluProject uses the model/world/projection matrix to project a 3d object to 2d coords. Simply use the matrices and transform the object.
What's the purpose of doing this (and not let the engine do it as it happens all the time during rendering).

BlindSide · Post by **BlindSide** » Tue Jul 10, 2007 1:30 am

Why do people say "i want to realise (something)". It kinda sounds weird..

Anyway I think you can times its transformation matrix by the inverted world matrix?

superpop · Post by **superpop** » Tue Jul 10, 2007 9:10 am

hybrid wrote:gluProject uses the model/world/projection matrix to project a 3d object to 2d coords. Simply use the matrices and transform the object.
What's the purpose of doing this (and not let the engine do it as it happens all the time during rendering).

Thank you.

superpop · Post by **superpop** » Tue Jul 10, 2007 9:11 am

BlindSide wrote:Why do people say "i want to realise (something)". It kinda sounds weird..

Anyway I think you can times its transformation matrix by the inverted world matrix?

BS u.