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View Full Version : :( Help please! Ray trace soft shadows in max?


Wes_Brown
06-16-2004, 05:00 PM
Hey guys. I have been a maya user since 1.0 and now I have to learn max. I like the program but there are some simple things I have not figured out yet. How do you get ray traced shadows to soften up? I am sure it is quite simple but I changed a few things under the ray trced shadows paramaters and I haven't found anythig. Any help would be greatly appreciated!!! Thanks in advance!!!!

robinb
06-16-2004, 05:18 PM
You want Area Shadows. They're a separate category of shadow type, although they do work the same as raytraced ones. Be prepared to play with the settings a lot to get decent output from them. But as you're used to using them in Maya, you should have a good starting point.

One thing that seems to catch people out is that by default there is an optimisation on that prevents them respecting transparency. It's in the optimisations rollout.

I assume you're not using Mental Ray. If so, then that has it's own shadow types.

thorn3d
06-16-2004, 08:15 PM
What i wouldn't give for ray-traced shadow maps in max...

thorn

Wes_Brown
06-16-2004, 10:16 PM
Hmm..I am very familliar with area shadows in maya but you can also get the same effect with ray traced shadows by increasing the rays and the light angle. no such luck in max? Are area shadows the only way?


Thanks again guys!

modern_night
06-16-2004, 10:25 PM
i think using raytraced shadows isn't agood idea :lightbulb
it will be very slow and it wont be good enough

any way

if you want to make a soft shadow using raytraced shadow you can change the parameters in raytraced shadow rollout ..
im at work now ..so i havnt the program and i dont remember the parameters names ..
its some thing like bias .. or spread.. but after you increase its value you will found alow quality shadow looks like soft shadows.
to increase the quality .. increase the value of the quality parameter.. or samples parameter .. i dont remember ..

and way .. if you still want to use it .. and u didnt know how to do that yet ..
i'll post you the how to do it ..
with right the parameters ;)

thorn3d
06-17-2004, 12:39 AM
That would be good to see an example, as i've never managed to make the following in max:

A volumetric light with a soft-edged shadow (non area), that will cast volumentric light through a surface with an opacity map.

thorn

robinb
06-17-2004, 09:58 AM
Actually, yes modern_night is right Advanced Raytrace shadows do allow you to spread them out and make soft edged shadows. I forgot about them. They aren't as nice as area shadows as they don't soften with distance, but they are a fair bit quicker to render. They look a lot like shadow maps, but they do respect transparency (the same optimisation as with area shadows is needed). I'd guess they wouldn't show up the pixelation of shadow maps when used on huge scenes.

And thorn3d- no, sadly volume light only works with shadow maps, so you can't make it work with opacity maps- boo.

thorn3d
06-17-2004, 11:57 AM
I've also tried Brazil and Vray lights... appears this is just a feature that either few want, or no one can code.

thorn

robinb
06-17-2004, 12:07 PM
The only way I found to deal with that problem was to have a real light making the raytraced shadows through the opacity map, and another one that didn't light or shadow anything, but just had the volume light effect on it. Of course that needs geometrical objects blocking it rather than opacity maps (I didn't actually need that). You could make vaguely similar proxy objects that aren't visible to the camera and place them in the opaque parts of the opacity map. A big pain to set all that up, depending on what you need it for.

I don't understand why people don't need that sort of functionality, you'd thing the most obvious use would be something like volume light shining through a tree with mapped leaves- that's basically impossible as it is.

Jeff Jones
07-17-2004, 04:53 AM
brazil lights work well for this, except the render times are horrible for this type of thing.

i dont think its possible to do raytraced soft shadows....

thorn3d
07-18-2004, 12:12 PM
Everyone's suggestions for "other light + proxy + gel + longer render" are nice, but if we just had a raytraced soft shadow it wouldn't require such workaround gymnastics. ;)

thorn

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