   No perspective!
  Hi Professionals.I want to know how to disable perspective when drawing a special object,the first thing i did was using glpushmatrix() and after that modified gluprespective but it didn't work.what is the best way to solve this problem.thanks alot;   
  Set the matrix mode to GL_PROJECTION, do glLoadIdentity(), and then possibly use glOrtho() or something to set up a non-perspective projection.   ;  You should be more specific on this. Disabling perspective means using another projection type, like ortographic projection. You can make an ortho projection by first switching to the projection matrix and then specify it with glOrtho; something like this:glMatrixMode(GL_MODELVIEW);glPushMatrix(); // push a new matrix for the modelview matrixglLoadIdentity();glMatrixMode(GL_PROJECTION);glPushMatrix();glLoadIDentity();glOrtho(left,right,bottom,top,nearVal,farVal);glMatrixMode(GL_MODELVIEW);// apply transformations and render the "special object"glPopMatrix();glMatrixMode(GL_PROJECTION);glPopMatrix();glMatrixMode(GL_MODELVIEW);