# How many points does the perspective in the viewport use and is it changeable?

I know blender can display both orthographic and perspective projection. But, when we look at a cube in blender's viewport, I'm unable to distinguish by eye, if the projection in the viewport is a one-point, a two-point or a three-point perspective. What does blender use, and is this something changeable?

• Isn't the distinction between one-, two- and threepoint perspective just for drawing? Dependent on the camera position, the 3D to 2D perspective projection will give you any of the three... Jul 13, 2020 at 11:20
• @haarigertroll , um... blender is basically drawing to the viewport, and the math seems to be different: people.eecs.berkeley.edu/~barsky/perspective.html Jul 13, 2020 at 11:22
• It's been a while since I had to calculate transformation matrices, but I think that the math is essentially the same, with just a different series of transformations. Take a look at these (same camera parameters, just different position gives you one, two or three vanishing points) i.stack.imgur.com/JKEx1.png i.stack.imgur.com/MZfTe.jpg i.stack.imgur.com/2PLcI.jpg Jul 13, 2020 at 11:30
• Addendum: It actually says so on your linked website (last paragraph): "Then the matrix for this 3-point perspective is: [...] And, the 1 point and 2 point perspective matrices are special cases with 1/dx and/or 1/dy equal to zero." Jul 13, 2020 at 11:30