That sounds like a good plan, I am going to try that out. However before I try, I want to draw the box and rotate it. However in the test code below the vec_rotate doesn't rotate the quad (just for testing) properly:

Code:
vec_fill(vMin, -200);
vec_fill(vMax, 200);
vec_rotate(vMin, vector(camera.pan, 0, 0));
vec_rotate(vMax, vector(camera.pan, 0, 0));
draw_line3d(vector(vMin.x, vMin.y, vMin.z),NULL,100);  
draw_line3d(vector(vMax.x, vMin.y, vMin.z),drawcolor_vec,100);
draw_line3d(vector(vMax.x, vMax.y, vMin.z),drawcolor_vec,100); 
draw_line3d(vector(vMin.x, vMax.y, vMin.z),drawcolor_vec,100); 
draw_line3d(vector(vMin.x, vMin.y, vMin.z),drawcolor_vec,100);


I am probably making some math error.