shadow bug

[marcel]

Ha my Bad english! i have difficulty to explain...
With smooth during rendering i mean the soft don't draw a egde between 2 faces but draw a gradient. as if the object was round. it is a simulation of the render engine as video card do to enhance low poly for game. "interpolation" is a kind of virtual sds created by soft or hardware. A technic as tesselation, a more complex function of video card.
TS don't create a gradiant instead the edge between 2 faces when they are at the limit of the shadow. It is why you have this bug. with a lot of face the bug is always here but too little to see it.
i don't know why the bug is more visible when you use bump. i need to see that and search if there is some setting to reduce the problem.

[bitkar]

well, in my research. I think using high poly object with highres bump and tweek the angle of light quite works. The bug is more visible on bumps that have smooth and large "hight transitions" than bumps with smaller patern. I thnk it will be ok after all and i will be able to acompllish my project (i hope it will not show up in some frames of animation or I will have to retouch it in post proces)

Luckily vray is fast enough to deal with high poly count and highres bump map.

So the summary could be:

high polycount, highres bump (the more complicated pater the better) and good light angle. Not to use bump is even better. There is no complete workaround unless someone makes some patch for tS that can solve the problem.

great thanks to marcel and bob!

[bitkar]

using area light helps much!!!