Cel-Shading WIP

SirSpangles

Hey everyone, I need a little help on getting the black outline around my models to make the cel shade complete. Duplicating the mesh and reversing the normals is not going to work so well here.

Anyone know of a good technique?

Obscura

Sobel Edge Detection
Duplicating would be cheaper.

BARDLER

It looks like you are kind of going for a borderlands style, but you should still be baking normals from a highpoly model. Running your diffuse through crazy bump is causing a lot of problems with the model, and is not a technique any studio employees in the industry. If you check out the Borderlands 2 art dump thread you can see some of the sculpting and detailing techniques they use in their models.

As for the black outline, what engine are you using for rendering? Marmoset simply has a button that lets you draw an outline, which is super easy.

SirSpangles

Yea I am going for a Borderlands style to this, I did see the art dump, that stuff looks amazing, I am going to try and do my best to achieve a similar outcome.

Right now this is in UDK, I believe duplicating the mesh will cause some issues cause my mesh isnt super simple. So it will create a lot of artifacting. There is a method on the UDN site as well but it is kind of ridiculous the way the node tree is set up.

As far as the normals go, crazybump was a fast and dirty way to get it done, theres not to much information in this model to do a transfer from high poly to low poly but for my new models that is what I am going to do.

SirSpangles

so i found a way on UDN.com to get the black outlines in UDK but Im not sure I want to do it that way, still looking for a more accurate and better way to execute it.

anyone know?

Vailias

Most complex effects, and yes cell shading with edge detection counts as complex, are going to have long shader node trees.

the exterior cell edgeing can come from 3 main ways. 1: duplicate the mesh, push it, flip normals, and apply the edge color.
2: a fresnel operator with a hard clamp set to black and multiplicative on your diffuse.
3: a sobel kernal operating on the framebuffer with a depth mask for input. This one is likely a good way to go with UDK, and I believe it is the one you found with the ridiculous node tree.

internal lines can be a separate texture or channel of your texture which are faded in and out via whatever masking method looks good. wider fresnel node, or a normal dot camera setup, that kind of thing.

SirSpangles

Thanks a lot man, that really narrows it down for me. You are correct I did find the sobel kernal operation, I wasnt sold on the outcome so I was hoping for a better route. Ill mess around with these and see what I get.