[vtkusers] Problem of projecting 3d points to an image plane

[york]

hi:

I am doing structure and motion. I want to project the 3D points I obtain by reconstruction to 2D points on the image using equation x = P * X, and P is projective matrix. According to this euqation, the transformation should be only related to projective matrix P, for P = k*[R t]. However, I found that in order to get proper transformation I have to set the ViewAngle value through:
                 objectRen->GetActiveCamera()->SetViewAngle()
So, could you tell me whether the projection is only related to projective matrix or any other factor? Thank you! 

Hou Dan
　　　　　　　
　　　　　　　　yorktim at bit.edu.cn
　　　　　　　　　　2005-09-07