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View Full Version : MR shadow map - needs too many samples

andrewjohn81
05-05-2005, 06:02 PM
For some reason I am requiring an insane amount of samples to get the shadow to look decent.

Here are my settings:
Map Size: 512
Sample Range: 0'0.01" (we need this in inches to make everything else easier)
Samples: 36

I am using a mr Area Omni with the Area Light Parameters tuned off. I am simply using the mr version to heed the warning of the messages the come up when you render. I get the same problem, though, with a normal omni.

Using 1 sample the shadow lookes like someone covered the shadow with hair. It isn't simply "dotty" like I would expect. It looks more like hair.
The region I am rendering took 11 seconds at 1 sample. I had to change it to 64 samples just to make it go up to 12 seconds. I was just testing to see if it made any difference in time.
Doesn't changing the samples usually double the time of each pixel that is effected?
I only need 36 to look good, so I am not complaining to much, but I think I may be missing the whole theory of what to do here. The help file isn't even correct, so I don't know to trust it. It's not a big deal, but it says the default settings are different than they are.

Any help appreciated.
Oh, and I'm using 7.5, so that means I have MR 3.4 if that makes a diff.
Maven
05-05-2005, 06:22 PM
Did you try useing a bigger map size. Like 1024 or 1536?
andrewjohn81
05-05-2005, 06:27 PM
I've never really thought of 1536, but that's a good intermediate number. I had to check to make sure it was divisible by the usual numbers. Even Squares, I've heard, are faster though.
I did try a higher value, but still have the same problem.
I tried 1536 with a sample value of 4.
I can't even figure out what it is trying to cast shadows on.
I can put the light in the center of the room and it still casts these patterns all over everything. It also is the only light on.
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05-05-2005, 06:27 PM
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