View Full Version : final gather noise with mia_physicalsky
07 July 2007, 10:41 PM
I have a problem with the physical sky and mental ray. Everywhere where geometry intersects with the physical sky I get those noisy quads. You can see it in the example image I rendered.
Does anyone know how to get rid off that?
07 July 2007, 12:29 PM
I had those artifacts when I mapped the haze attriubute with a texture. My mistake was to use an envSphere node between the file texture and the physicalSky. The solution is to map the file texture directly to the haze attribute.
I was surprised to find that physicalSky uses a spherical projection internally and maps the file texture to the upper hemisphere (depends on the horizon height) the seam ends up on the +z axis, but you can use the place2dTexture offset U attribute to reposition it.
07 July 2007, 09:07 PM
thanks I'll try that. I did the same thing :)
07 July 2007, 10:57 PM
thats seems to work, great!
But now I get those strange artefacts on the ground because the cloud texture is also piped into the haze attribute of the physical sun shader. If I disconnect it then it works but I was wondering if I can also control the haze of the physical sun shader with the cloud texture?
07 July 2007, 12:32 AM
I have a similar network setup. At first I tried using the maya environment lookup nodes so I could use their 3d texture placement to aim the sky background but that caused those same blocky Final Gather errors. I found that if you use the mental ray spherical lookup you dont get those FG errors.
If anyone can figure out a way to have more adjustments or control on the mental ray spherical lookup node, i'd be interested to hear your suggestions. The multiply/divide nodes are for independantly adjusting the amount of effect the texture has on the haze and background.
07 July 2007, 11:06 PM
is it possible to put the sun behind the clouds? It is always in front of them.
07 July 2007, 02:06 PM
If anyone can figure out a way to have more adjustments or control on the mental ray spherical lookup node, i'd be interested to hear your suggestions.
I'm curious about that as well! Is there any way to make the texture visible in the viewport?
07 July 2007, 02:06 PM
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