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seen May 18 '13 at 13:23

Sep
16
awarded  Popular Question
Feb
23
comment Mapping 3D object coordinates to 2D screen coordinates with perspective projection
I think the matrix multiplications are in the correct order. I'm not entirely sure but I think it has something to do with the last division of the x and y components by the z. Here's my most recent Camera3D class where I organise the matrices and render the points. Can you spot any errors that would cause the points to render in the opposite corner after passing the Z value of the camera (behind): pastebin.com/NGGHpqGv
Feb
21
comment Mapping 3D object coordinates to 2D screen coordinates with perspective projection
This is great but the problem I'm having is when the Z component is negative and supposedly out of the frame and behind the camera, it appears to just come back into the screen from the opposite corner of the screen. e.g. A point at coordinate 1:1:0 should be in the top right corner of the screen. If I increase its Z component it moves forward as expected, but if I decrease it, rather than moving behind the scene and not being rendered, it begins to move in from the bottom left hand corner towards the centre of the screen, in this example.
Feb
20
awarded  Scholar
Feb
20
accepted Mapping 3D object coordinates to 2D screen coordinates with perspective projection
Feb
20
comment Mapping 3D object coordinates to 2D screen coordinates with perspective projection
Ah, it seems to be working now. Thanks to everyone for your help! Also, I'm not sure why but the X axis seems to be flipped for my coordinate system and I'm not sure why. Anyway, I'll hopefully figure out why that is.
Feb
19
awarded  Student
Feb
19
awarded  Editor
Feb
19
revised Mapping 3D object coordinates to 2D screen coordinates with perspective projection
deleted 4 characters in body
Feb
19
asked Mapping 3D object coordinates to 2D screen coordinates with perspective projection