ransformation: object to eye coordinates

Hi all,

I’m in trouble with a transformation. I have to transform a vertex with the actual matrix. Here ist the codefragment:

GLdouble mat[16];


glTranslated(dx, dy, dz);

glGetDoublev(GL_MODELVIEW_MATRIX, mat);

at this point I should have the matrix use by OpenGl to transform vertizees according to the actual translate, rotate and stretch values saved in the array mat.

glVertex3d(v0.x, v0.y, v0.z);


the following calculation should have the same result vor v0

xEye = mat[0]*v0.x + mat[4]*v0.y + mat[8]*v0.z + mat[12];
yEye = mat[1]*v0.x + mat[5]*v0.y + mat[9]*v0.z + mat[13];
zEye = mat[2]*v0.x + mat[6]*v0.y + mat[10]*v0.z + mat[14];

Is this correct?
Is there a better way to do this calculation, probably any openGl function?

Thank you all for your help!

Open GL does not include vector matrix multiplication.
You will need to implement your own matrix class to handle that.
Looks like you have started that process already.