View Full Version : how to make soft raytraced shadows in maya??

03 March 2002, 02:48 PM
anyone know???
'cause my depth map shadows keep on flickering. well from what i could tell, it was the self-cast shadow on my character which was flickering the most. as though the resolution of the map was too low. though i was at 4096 already. the shadows on the rest of the scene looked okay. my character is a poly character. i was using a spot light with no decay, cone angle 47 (though at quite a distance away from the character), mid dist dmap and use dmap auto focus were on, filter at 5, bias at .001
i've been trying to figure this out with a loooong time now with no success it seems. anyone know?
or else i'll just switch to raytraced. so if i do, how would i make them soft?

07 July 2005, 10:07 PM

First off, I don't think you need a 4k dmap... That's huge. 2k or even 1k should work ok, unless you are rendering some gigantic frames or your scene scale is very very large and your light is linked to everything in the scene (which is not a good idea).

Even when using dmaps, you'll want to create a light rig to make soft shadows, rather than expecting it from 1 spot.
play with the dmap filtering, if you haven't done so already. Crank it up a bit. Also, you should use lights solely for your character, unlink them from the rest of your scene... Keep only the objects that will have shadows cast on by your character. Your DMAP will be spread over all the objects that the light is linked to. That way you can get away with using smaller dmaps and still get accurate shadows without choppy edges.

Soft raytraced shadows are a bit trickier. If using Maya renderer you can set a couple area lights to behave like a studio lightbox. Turn raytraced shadows on them. You can also try creating a multiple spotlight rig. use multiple shadow rays. A little post blur on the shadow pass can be done.

07 July 2005, 07:47 PM
you can get soft raytraced shadows by simply opening up the Raytrace Shadow Attributes and increasing the Light Radius from 0 to some number and increasing the number of Shadow Rays. 0 radius/1 ray is a point light. The bigger the radius, the softer the shadow will be. You'll need to crank up the number of Shadow Rays to eliminate the pixelated look of the shadow.

Of course, your rendering time will take a significant hit doing this though :) You might want to explore using a light rig with depth maps instead..

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07 July 2005, 07:47 PM
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