Stacked 3D layers + cast shadows: Annoying artefacts

Adobe After Effects

Stacked 3D layers + cast shadows: Annoying artefacts

Posted by Julien Coudert on February 1, 2012 at 2:03 pm

hi there,

First post here and glad to become a creative cow member!
here is the problem i have on many scenes i do:

When stacking couple 3d layers on my scene with a light and cast shadows turned on, some artefacts start appearing. I do whatever is possible not to stack them at exact same position, trying to let space between them, but some noise still occure.

here a link to a screenshot: https://imageshack.us/photo/my-images/51/projecta.jpg/

If any of you guys have a tip to avoid such annoying thing, it would be much appreciated!

Thx

Roland R. kahlenberg replied 14 years, 6 months ago 4 Members · 5 Replies
5 Replies

Tudor “ted” jelescu
February 1, 2012 at 5:54 pm

If you are using OpenGL, turn that off. Play with the distance between layers and see if the artefact still appears at a bigger distance.
Do you have any 2d layers in between your 3d layers?

Tudor “Ted” Jelescu
Senior VFX Artist
Darby Edelen
February 1, 2012 at 7:04 pm

Also you can change the Shadow Map resolution by clicking on the “Options…” button next to the renderer in the Advanced tab of your Composition Settings (cmd-k/ctrl-k mac/pc).

The default shadow map resolution is based on the resolution of the composition. This is usually okay, but if you need additional accuracy you can choose a resolution up to 4000px. This will increase render time and uses more memory but should give you more accurate shadows.

Darby Edelen
Roland R. kahlenberg
February 1, 2012 at 9:41 pm

This is the dreaded 3D shadow problem that has been around forever!!! The result actually looks like a low rez render.

I suggest that you send this AEP and JPG to the AE Team. They’ve been sitting on this problem for close to 10 years!!!

Moving the two layers (shadow casting & shadow catcher) further apart usually helps. Using Point instead Spotlights also help. Adjusting the orientation/rotation of the light may also help.

Cheers
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer
Julien Coudert
February 2, 2012 at 8:09 am

thanks for all your fast reply guys.

You are right 2D layers between 3D layers make the shadows completly disapear in camera view only (shadows appear in other views). Weird thing.

I solved my problem using maximum shadow resolution set to 4000 and making sure no layers are stacked, artefacts totaly dispears.

Good motion to everyone, see ya!
Roland R. kahlenberg
February 3, 2012 at 12:38 am

[julien coudert] “You are right 2D layers between 3D layers make the shadows completly disapear in camera view only (shadows appear in other views). Weird thing.”

This isn’t weird. This is how 2D layers affect the interaction between 3D layers.

[julien coudert] “I solved my problem using maximum shadow resolution set to 4000 and making sure no layers are stacked, artefacts totaly dispears.”

You’re lucky that this works for you. I’m pretty certain that if youhad more layers in the comp, that raising the shadow map will not solve the issue. It’s definitely a memory/algorithm issue.

Cheers
RoRK

Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer

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