Strange 3D lighting anomaly

[Filip Vandueren]

It’s a problem with the way shadows are calculated in After Effects.

If you set the softness to zero, you’ll still see you’re not getting sharp shadows: they get interpolated froma pre-calculated shadow map: a bitmap with limited resolution that is projected onto the layers. No true ‘raytracing’ is used.

Think of the shadowmap as a pre-render with the camera looking from the light: if the there is a layer that is very small from the light’s point of view (it is very far away)) then that feature could be just a few pixels worth of ‘shadow information’: if you zoom into that layer’s shadow: you’ll see a big blur.
So: keep that in mind: never have your shadowcasting spotlights to far away.
Try to avoid using Point lights as shadowcasters: they store the shadowinformation with even less precision because they are like 2 very wide spotlights, one looking ahead, and one behind, spanning the entire 360

[Blair Mcnaughton]

Thanks! Huge help! But yeah, render times are nuts… 40+ hours for a 16 second clip at DV resolution… yikes!

[Filip Vandueren]

See if turning off all shadow diffusion is acceptable. That’s the biggest slowdown.