I’m have a strange problem with Krakatoa where I’m trying to make a solid object out of particles which then gets affected by a wind force and a deflector travelling through the object to active the wind force’s influence on the particle mass. So I created a particle object using the “object position” widget and filled the object using the surface(not volume which seems to be much slower and not make much difference visually)
So basically whats happening is that the particles mass isn’t uniformly distributed and there seems to be a kind of banding thats going on with lines of shadow and lighter sections. I’ve tried adding more or less particles but that doesn’t seem to have much effect(adding/subtracting a million particles) I’ve also played with the density settings but that doesn’t seem to have much effect either, the current setting are density per particle 15.0 and density -5 and 2 million particles.
Some things you could try (frankly Chad is more experienced in this area )
*Try enabling the independent density controls for the Lighting pass and set the density per particle even lower. This will keep the density of the final pass the same, while making the particles more transparent to the light.
*Try changing the size of the Shadow Map in your light. The default is 512. Try going down to something like 64 and see if the banding changes.
Chad had also some experiments with multiple lights using various map size settings and/or rotated at various angles about their Z axis. But in general moire patterns mean that the density per particle might be too high, resulting in self-shadowing. See this article for some background info: franticfilms.com/software/su … ensity.php
Yeah, do a rendering without lighting at all, and see if the problem goes away. If so, it’s the shadows. Changing the density will “fix” it, but then your density will be too low, which may be unacceptable in some cases. So your only recourse is to change the lighting/shadows themselves. Try rotating the light around the Z axis, or changing the map size. If either of these changes the pattern, then just tweak until it goes away. Don’t be afraid to add LOTS of lights.
sorry guys I thought I’d get an email when someone posted a response so only see now that someone has responded… I’ll try these solutions tonight and see if I can get anywhere.
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