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ColinCohen
10-03-2005, 02:28 PM
I'm experimenting with NPR and I have question about rendering edges. As you can see, in the frontal image, LW finds the edges within the inner ear. But from the side, it doesn't.

Does anyone know why?

Celshader
10-03-2005, 02:39 PM
I'm experimenting with NPR and I have question about rendering edges. As you can see, in the frontal image, LW finds the edges within the inner ear. But from the side, it doesn't.

Does anyone know why?

You have enough of an angle when viewed from the front, but not enough of a change in angle from the side view. This is why I do not trust angle-based inking like Fresnel Edges, Bumped Edges or an Incidence Angle gradient.

You can exaggerate the angles of the inner ear to guarantee angle-based edges from all angles, but you're still dealing with a dangerously unpredictable inking tool.

For my stuff, it's Edges all the way for me:
http://www.celshader.com/gallery/kara/about4.htm

ColinCohen
10-03-2005, 02:59 PM
Thanks, Jennifer! I was hoping you'd see this. :)

The thing is, in additional to Bumped Edges, I'm using standard Silhouette and Unshared Edges. Here's the same images with only LW edges.

But I'll try exaggerating the angles.

Again, thanks.

Celshader
10-03-2005, 03:15 PM
If it helps, look at how I sculpted Lore's (http://www.celshader.com/gallery/lore/) ear. I posted a modified copy of it on TurboSquid with lots of screenshots, so you can closely inspect the geometry here:
http://www.turbosquid.com/HTMLClient/FullPreview/FullPreview.cfm/ID/199220/Action/FullPreview

Login and look at the Quicktime preview of the ear turnaround. The only difference between this geometry and Lore's ear is that I rounded the tip to make it look more human. The internal parts of the ear are identical.

That said, my ink lines disappear occasionally, too:
http://www.celshader.com/gallery/lore/lore-blink.mov

...but I have the deepest parts of the ear flat-shaded with the same color as the ink line, so those parts of the ear are always "inked."

ColinCohen
10-03-2005, 03:24 PM
Thanks for the great tips.

If you ever decided to write a book exclusively dedicated to cel-shading/npr, I'd be the first buyer. And certainly not the only one.