toon line buzzing & stylized highlight having seams

[adriyantandia]

Hi ! I have a question, do you guys I tried to make a thick toon line so in a contour filter I put in 10 for the filter width, and I have tried to lock the sampling, clamp the pixel as well but seems like when I was rendering a turnaround, the transition didn't feel that consistent, it feels like buzzing for a bit. I had my AA sampling in 6, is it only the AA sampling issues ? or is there anything that I miss here ?

And also want to double check since I am curious and seems like I haven't seen any answers regarding this online, does the stylized highlight would have seams if we assign a ramp into the highlight color of it ? since seems like in the documentation it looks like there's no seams when it says that you can apply a ramp, if there is a way to have it without seams, how do I do it ?

I will try to put in images as soon as possible.

Thank you !
Adriyan

[lee_griggs]

1. A contour filter_width of 10 seems way too high and would take a long time to render. Is there a reason it needs to be so high? Do you have any images to show?
2. I see the issue. smooth_tangents seems to fix it (under subdivision). I will add a note to the docs. Thanks for the feedback!

[adriyantandia]

Hi ! thanks for the reply and sorry for the late reply

1. I do need it since the toon lines we need has a variation for thin and thick lines, and sorry that I can't show the images because of NDA. But I managed to fix that up by reducing the mipmap of the textures that is connected to the edge width of the toon shader. I'll try to show the issue again if I can recreate it in a simple obj !

2. Thank you, but that seems more like a staircase (low poly) problem rather than a seam problem , in the image that I added below as you can see when I change the UV of the sphere from its default (those zigzaggy planes) into a split sphere, and this issue shows up. I was thinking of painting a map but I have no idea how to have a map that controls the ramp of the spec dynamically. thanks ! 🙂

[ramon.montoya]

Regarding 2:

The toon shader relies on uv maps to compute a smooth tangent, without one you might get discontinuities at polygon edges, or patch edges for subdivs.

If you assign uvs, the discontinuities will only be visible where the uv map has a seam.

You can also attach a tangent source directly to `toon.tangent`, but hiding the uv seams might be easier.

[ramon.montoya]

And as a comment for clarity:

The toon shader relies on uv maps to compute a smooth tangent, without one you might get discontinuities at polygon edges, or patch edges for subdivs.

If you assign uvs, the discontinuities will only be visible where the uv map has a seam.

You can also attach a tangent source directly to `toon.tangent`, but hiding the uv seams might be easier.

[adriyantandia]

hi Ramon ! thanks for the answers ! when you said attaching 'tangent source' directly toon tangent, do you mean it as pluggin in the normal into the tangent similar to what shown in the link here ? (using ai utility) https://cgrenderdna.blogspot.com/2018/06/arnold-render-anisotropy-tangent-fix-uv.html

thanks !