we have a problem with one of our older projects that we’ve tried to render with Vray 2 but found out that this problem exists already since Vray 1.5 SP4.
It is a model of a truck where we have used VrayToon in combination with a transparent Material. On the Image below you see the Wheel case of the truck and the problem we ran into. The left image ist done with Vray SP3 and the right with SP4. In the Change Log of SP4 one of the bug fixes was “Fixed issue with VRayToon and opacity mapped objects” which is exactly our case. But i don’t understand how this takes effect on our model and how we can fix that. it seems to be a problem with the Distance threshold because at the white areas the faces are really close to each other, but even with the lowest value we don’t get it to look like in SP3.
Apart from some overlapping faces, which are always going to be a problem, switching to pixel width seems to work much better (the scene was set to world width of 1 unit, which seemed too high). Reducing the line width to 0.4 for example, also works well.
You can also reduce the “trace bias” parameter in V-Ray toon a bit to get some more definition in the lines.
Ok, we tried it out now. Changing the trace bias worked the best. Unfortunately we can not switch to pixel units because in the animation we have close-ups and than long-shots and especially in the long shots the lines can became pretty dense when using pixel units. But the thing with the trace bias in VrayToon also remembered me that there is the secondary rays bias in the Vray Global switches rollout. Putting this parameter to a higher value also had a positive effect.
