FOV bug?

Mobius · Post by **Mobius** » Tue Aug 22, 2006 8:47 am

I think that the FOV in buildProjectionMatrixPerspectiveFovLH/RH
methods are wrong calculated.

In fact, if I restrict the field of view I obtain a zoom out, not a zoom in.
I also tried a patch found at hybryd page, but it doesn't work.

Then I looked the GLUPerspective function:
http://developer.apple.com/documentatio ... ive.3.html

If I use

(*this)(0,0) = h / aspectRatio;
(*this)(1,1) = h;

instead of the original settings, FOV seems to work.

Is it a bug?

Electron · Post by **Electron** » Tue Aug 22, 2006 12:08 pm

I believe Rv had it right here http://irrlicht.sourceforge.net/phpBB2/ ... hp?t=12426. This is the projection matrix code Lightfeather uses, and it seems to work well

Mobius · Post by **Mobius** » Tue Aug 22, 2006 1:58 pm

Ok, that confirms my version... thanks!

Spintz · Post by **Spintz** » Tue Aug 22, 2006 7:26 pm

The Irrlicht one works fine for me, If I use that one from that post, my FOV gets all screwed up and everything looks elongated.

Electron · Post by **Electron** » Tue Aug 22, 2006 9:32 pm

Using Rv's version a normal FOV is pi/3 rad (60 degrees) instead of pi/2 rad (90 degrees). That should look fine. Rv's version doesn't go crazy when you move the near plane, which the original version does.

hybrid · Post by **hybrid** » Tue Aug 29, 2006 12:52 am

Ok, both DirectX and OpenGL used something like this, so I have changed all 6 projection matrices to the DirectX default from MSDN. Please try this version (e.g. by copying matrix4.h from SVN to your code or directly using SVN) and report problems back.
The strange aspect ratio was due to a "fix" for the corrected aspect ratio several versions ago. We had to multiply with the aspect ratio to get the Irrlicht matrices working correctly. However, now this had to be changed back