light shadows when brightness is 0

lakeivan

Hi folks,

This is just something I'm confused about. I notice that, with an animation I'm making, I keyframe the brightness on one of the spot lights to go from 75 down to 0. But after the frame where the brightness is 0, it still seems to be casting a shadow of some kind or other, which weirdly has the effect of making the object which the light is pointing towards brighter. It is not set to have a negative shadow, just a normal hard shadow at 100% shadow darkness. I would have assumed that, when the brightness of a light is at 0, it would no longer have any visible shadow. This means that this spot light is still affecting the light in the scene, even when its brightness is 0. I can do some complicated stuff to work around this, but I'm confused about the nature of the shadow, and why it makes a difference, even when the light is at 0 brightness. If I turn visibility for this light off, then it truly has no effect (of course). Thanks in advance for any clarification. There are no "light effects" on this light except a very slight light cone, but turning this off has no effect on the weird shadow light I'm seeing.

Richard Haseltine

So this is in the frame where it is at zero? Otherwise it might be interpolation giving it a negative value after the sero frame, though it's hard to follow exactly what is happening.

RuudL

I was able to reproduce the problem you decribed.

My solution: modify the tweener by setting the right slider of the 'Ease In-Out' to about 90%. And use the same settings of the 'Brightness' channel for the 'Shadow Intensity' channel. 

lakeivan

Ruudl thanks for the great tip, if I can ever get Carrara to open again without crashing, I'll try that1