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JaMo
04-01-2006, 10:09 PM
ive redner out a color pass and shadow pass but when i go to composite them together the shadow pass is screwed up. im using maya 6.5 for rendering and AE 5.5 for compositing.

here is what im doing.

i am rendering out to .rla's
the camera's environment is set to white
i bring the color and shadow pass into AE as premultiplied with white.
i put the shadow layer on top of the color layer

here is an image to show exactly whats going on. on the left is a maya rendering with no passes and on the right are the passes composited in AE. you can see how the right image has shadows screwed up. anyone know what im doing wrong?

http://www.geocities.com/feedback3d/example.jpg

tedious
04-02-2006, 12:39 AM
It looks as if you are using a blue shadow color on the left, but maya's shadow passes don't do shadow color, so the shadows are going all the way black on the right? Is that the problem?

tedious

JaMo
04-02-2006, 12:58 AM
It looks as if you are using a blue shadow color on the left, but maya's shadow passes don't do shadow color, so the shadows are going all the way black on the right? Is that the problem?

tedious

the color isnt the problem but it maybe whats causing the problem. if you look at the picture the shadows on the left are falling on the model properly but on the right it very messed up.

it just occured to me that it might be the cloth being a seperate object is casting shadow onto the model also. so when i put the shadow layer on top in AE its putting the shadow from the cloth on top instead of being underneatth the cloth. seems that it would be masked off though so im not sure if thats it or not.

tedious
04-02-2006, 01:02 AM
Good point. I wouldn't expect your shadow pass to work perfectly for shadows on that translucent cloth. Could you render the attached shadows (shadows of the character, onto the character) as a part of the character layer? Then the only thing you need in the shadow pass is the shadow cast onto the background objects (you could use a layer override to turn off primary visibility for the character and her cloth in the shadow pass layer) and most of your problems would be fixed?

tedious

JaMo
04-02-2006, 01:08 AM
Good point. I wouldn't expect your shadow pass to work perfectly for shadows on that translucent cloth. Could you render the attached shadows (shadows of the character, onto the character) as a part of the character layer? Then the only thing you need in the shadow pass is the shadow cast onto the background objects (you could use a layer override to turn off primary visibility for the character and her cloth in the shadow pass layer) and most of your problems would be fixed?

tedious

well to be honest i was hoping to not have to re render this because it took a long time. i have rendered out alot and rendered the shadows seperate because i figured it would save me time but so far its just giving me a headache.

btw im having some shadow problems similar to this on antoher model where there is no transparency.=(


why would the shadow change just because its rendered in layers. shouldnt it be the exact same in both situations?

JaMo
04-02-2006, 03:41 AM
tedious: you were right about the trans messing with the shadow layer. i still have a problem with the shadows rendering differently though.

in this image the render on the left is render without seperate passes. on the right i have rendered the shadow pass seperatly and when i go to composite it looks different then when i render it in maya. any ideas?

http://www.geocities.com/feedback3d/example2.jpg

leigh
04-02-2006, 03:49 AM
When you are rendering these out in seperate layers, how are you rendering out the layer without shadows? Because when I look at that last render comparison you posted, it looks like there is something wrong with your actual shading, and that's why the shadows look strange. In the non-layered render, the darker areas are not all caused by shadows, part of the darkening is the actual shading of the shader model, and that appears to be a bit weird in your pass that shows the seperate render layers. If you're going to render out your scene in seperate passes, you should have at least different passes for diffuse, specular and shadow. This should technically look the same as a straight beauty pass, since the shadows should technically meet the shaded areas without a visible edge (although depending on the method used to render the shadows, the shadow pass could need tweaking before you get the desired result).

JaMo
04-02-2006, 04:15 AM
When you are rendering these out in seperate layers, how are you rendering out the layer without shadows? Because when I look at that last render comparison you posted, it looks like there is something wrong with your actual shading, and that's why the shadows look strange. In the non-layered render, the darker areas are not all caused by shadows, part of the darkening is the actual shading of the shader model, and that appears to be a bit weird in your pass that shows the seperate render layers. If you're going to render out your scene in seperate passes, you should have at least different passes for diffuse, specular and shadow. This should technically look the same as a straight beauty pass, since the shadows should technically meet the shaded areas without a visible edge (although depending on the method used to render the shadows, the shadow pass could need tweaking before you get the desired result).

the pass without the shadow is the color pass. it includes diffuse and spec but not shadows. maya docs say its ok to render this pass and a shadow pass or if you need to, break the color down into its two parts. the material is just a grey lambert so the shading is from the lighting i have in the scene.(its set up for a different angle)

here is a picture with no shadows. i do not understand why the shadows would be different just because i render it in a pass. it seems like it should be exactly the same.


http://www.geocities.com/feedback3d/no_shadows.jpg

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