Hello,
I have a problem with the VraySun shadows on the trunk :
I first thank it was a bias problem but changing the bias on the VraySun doesn’t help anything.
The tree is an imported mesh, so I tank a units problem, but a Rest X-form + collapse stack on the tree gives the same problem !
There is no GI and no other sources of light.
What is missing ?
Thanks for your help 
Hi,
Can you post the scene file here or send it to support at chaosgroup.com?
is your bump map turned up too high? it can cause issues as it warps the normals too far.
Thank you for help !
It was just a problem of smoothing !
The mesh was too edgy, problem disappears with a Turbosmooth modifier. I missed that…
Anyway, thank you very much !
shadow problem.zip (187 KB)
Glad to hear that you 've found solution for this.
The shadow cast by the V-Ray sun are very crisp and such results are expected with low poly objects.
