glm::unProject with perspective projection matrix fails

[alzhuravlev]

file: glm/gtc/matrix_transform.inl
method: glm::unProject

Actual:
...
tmp = tmp * T(2) - T(1);
...

Expected:
...
tmp.x = tmp.x * T(2) - T(1);
tmp.y = tmp.y * T(2) - T(1);
...

Otherwise when we unproject value in perspective projection depth value (tmp.z) will be corrupted by tmp * T(2) - T(1);

[Groovounet]

Hi,

That's an interesting report which is actually a feature request, not a bug.
My guess is that you might be a Direct3D user or a software rendering user.

It's odd but OpenGL Z axis is actually define between -1 and 1 on the contrary with Direct3D that defines it between 0 and 1. So I guess I need to add functions for [0, 1] for both "unProject" and "project", not sure what to call them....

Thanks,
Christophe

[JesseTG]

Has this been fixed already? 0.9.6 was a while ago.

[Groovounet]

This wasn't fixed, I applied the proposed fix but I probably need to double check the math...

[JesseTG]

Ah, ok. Could've sworn I'd seen something like this in the code base somewhere before...

[Groovounet]

This is fixed in GLM 0.9.8.

Thanks,
Christophe