Projection of 3D points on the camera plane

Luper · March 21, 2025, 4:33pm

Hello beautiful people!
Very simple problem: how can I know the coordinates on the screen (2D) of points in 3D space?

Let me explain better: I have a certain number of points in 3D space (x,y,z), and I have to calculate what are the X Y coordinates of their representation in the render plane

PointsInSpace.v4p (7.6 KB)

readme · March 21, 2025, 5:06pm

Hi, maybe this help patch is going to help you:
HowTo Overlay 3D Objects with 2D Skia

Edit: Sorry, didn’t notice it was beta.
Just try multiplying your 3D points with the ViewProjection Matrix of your camera

antokhio · March 21, 2025, 6:27pm

It’s view * projection then inverse and * (3d Transform)

Luper · March 21, 2025, 6:59pm

Thanks! I did just View*Projection and then ApplyTransform.
But it works also using ViewProjection.

so I guess ViewProjection=View*Projection?

readme · March 21, 2025, 9:24pm

Yes, it is. These are just already multiplied matrices.