>
> Actually, I do not understand why the vertical wall (mesh) seems to show the
> effect of random rotation of sample ray direction (which leads to the
> expected noisy looking illumination) whereas the plane primitive for ground
> has a regular "projection-like" illumination.
>

Jerome,

Excellent work (and timing)! The above effect you illustrate is exactly the
effect I was talking about in my recent post. I'll bet the normals on the
ground are all facing in the Z direction. The Megapov radiosity code does
not do the random rotation if the surface normal is pointing near the Z
axis. Since your ground is flat, all the normals point the same way. That
is, they are all parallel to the world's Z axis. Thus none of them get the
random rotation that you requested in your radiosity {} block. I believe
this is a bug in the code and your picture has helped convince me. Thanks!


> In addition, I noticed the recent issue raised by George Pantazopoulos too
> (randomized sample direction rotation which is less effective for samples
> taken from a near-normal direction. The effect is noticeable in scenes with
> small bright sources (in a "cornell box"-like scene for instance))
>
>
That isn't the effect I described in my recent post. The problem I described
is that if the surface point's normal happens to be (nearly) parallel to
the World Z axis, no random rotation is done at all. I'd be interested in a
picture and more info about this particular effect.

Regards,
George

http://www.gammaburst.net

Post a reply to this message