adjusting shadows on alpha help

[bearfoot]

hello

i think generally for this kind of thing ..you can either..

change the color of the shadow in the light properties..

Render a shadow pass seperatley and comp after adjusting opacity in your comp program

enable radiosity for the ground plane only using your source plate as the image source

or maybe adjust the diffuse and lumositiy of the ground plane to match the plate..

hope that helps
n

[lazyanimator]

thanks bearfoot, I will have a try at each of your suggestions. Unusually I am creating the background plates after primary animation is rendered which is what is screwing this all up. Otherwise I could have used front projection.

[softdistortion]

It's really worth the effort to set up a buffer export.

Using EXR is optimal, but you can also use jpeg or tiff etc by setting up multiple instances of LWs native buffer export to save out the various images to separate folders.

You should set up one buffer pass to render without any shadows ... that allows you to isolate your character object. Then you can set your shadow pass to the density and color you want it to be.

[lazyanimator]

thanks softdistortion.



Could you clarify wheather it is necessary to render each sequence twice (once with shadows tuned off to get the beauty and alpha, then again with shadows turned back on with buffer shadow selected) or is there a method of rendering all of this just once with the ability to turn shadows off for beauty and alpha but on for the shadow buffer image? As you can tell I am pretty new to using the buffers...

[softdistortion]

Here's some reading that might help you out a bit>

http://www.adobe.com/devnet/aftereffects/articles/3d_integration_pt2_print.html
http://www.adobe.com/devnet/aftereffects/articles/3d_integration_pt2_08.html

[lazyanimator]

thanks so much for your help, I will certainly take a look at these.


One thing that I am finding is that when comped in after effects my alpha is leaving a nasty black outline around my character (I assume an anti alaising artifact) . Is there anything that can be done to get rid of this? Have tried various keying techniques but with no joy!

[softdistortion]

This is a copy paste info you need to look at for your issue mentioned above...from the first link above (put the effort in to read and understand the links info...it's got most of what you need to know in there for LW>AE ) ;)

Make sure your footage interpretation is correct. There is a crucial difference between premultiplied and straight (unmultiplied) alpha, and setting this wrong can mess up things from the start.

[lazyanimator]

Thanks and appologies for the late reply. Man, everything is sooo complicated!! I'll give it all a good read! and then decide to go into farming or somthing...

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