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View Full Version : Toon Shading or a "Crisp Vector Look" ??


skuby
10-31-2006, 03:50 PM
Hi guys. I've been contracted to convert some industrial building blue-prints into 3D represenations and the client would prefer the rendering to look something as I would describe as an ultra crisp toon shading or 3D Vector rendering.

To make it easier to describe exactly here's a sample image taken from an advertisement for Google's Sketch Up program. That specifically is the rendering style they are looking for.

http://img2.freeimagehosting.net/image.php?b45f768295.jpg

My question is. Can this be done completely with-in XSI?

I've been fiddling with the toon shader with mixed results. I can't make the lines super thin and crisp without the render-er failing to render full lines when I lower the "ink spread". Nor can I figure out how to get the renderer to do anti-ailiasing (this might be a basic problem fix as I know little about rendering in XSI). If I could fix these two problems I'm convinced that I could get some nice renders out of XSI but I'm open to other solutions.

Here are some shots of my mixed Toon Shader results so far...

http://img2.freeimagehosting.net/image.php?b074409102.jpg
http://img2.freeimagehosting.net/uploads/3c470cf3bc.jpg

And here's what happens when I use the "ink spread" to try and thin the lines (the "choppiness" ...)

http://img2.freeimagehosting.net/image.php?6f9534fc9d.jpg

It would be truely awsome if someone could render just a simple box primitive in the style from the first picture and then share with me the process for achieving that crisp result. Any help/suggestion is greatly appreciated. -Derek

Gene Williams
10-31-2006, 04:05 PM
Think this might be what you are looking for:
http://www.3dluvr.com/rogueldr/tutorials/toon_ink/toon_ink.html

Gene

kimaldis
10-31-2006, 06:20 PM
anti-aliasing is the key to getting quality toon lines in mental ray. The thinner the lines the higher the aa needs to be and the trick is to raise the min level until it approaches or equals the max level. Start with 1,2, go to 2,2 if you need to. On rare occasions, possibly your case, 2,3 and even rarer, 3,3.

you should also look at the sampling levels in the toon shader. This will also make a difference.

your render times could go quite high, especially as the line get thinner. But it's a good look.

Sbowling
11-01-2006, 03:30 AM
Kim has some great videos on the softimage site about Toon shading and ink lines. Definitely worth watching.

Tekano
11-01-2006, 10:07 AM
and biggin up ol' Kim(Aldis) some more whilst keepin on topic, isnt he going to release an .eps frame exporter soon? Cant get much cleaner and crisper than vectors now eh? speaking of which I still have a version of the swift3D exporter for xsi. this actually works in v5 but not v4.2 funnily enouh. this would be perfect for you , unfortunately erain stopped selling and supporting this due to lack of sales. I think me and one other guy purchased it...

kimaldis
11-01-2006, 11:06 AM
I've nearly got it finished, Rob. I gave Olly a copy to play with at the weekend and now I'm just trying to find an hour or so to write some useage notes.

I takes a pretty simple-minded approach to hidden surface, just hides back facing polys right now. I've some plans to add a Painter's algorithm, which should make it a bit better but true hidden surface is a bit tougher.

Only does poly meshes so far.

I've also set up something that allows you to define separate line thicknesses for inner and sillhoutette borders which looks quite groovy.

You're right, though, you should get pretty good quality lines with eps. You could render off the fill in XSI and lay the eps over the top.

skuby
11-01-2006, 01:07 PM
Thanks Kimaldis, I will look more closely at anti-aliasing. BTW are you the same Kim that everyone is refering to? Because I would really like to get my hands on that .SWF plug-in that works with v5, would also love to check out .EPS rendering. If you could hook me up it would be most appreciated -Derek


UPDATE: Anti-aliasing did the trick. I can get away with 1 and 2 but 2/2 and 3/3 min/max certaintly does look a little better but the render times are already rediculous at 1/2. Thanks so much for the solution, I was pulling my hair out with so many options to fiddle with and now I'm getting crisp results.

mocaw
11-01-2006, 06:26 PM
Deleted due to brain malfunction...

kimaldis
11-01-2006, 08:44 PM
[QUOTE=mocaw]Don't forget that sometimes it's faster to render out a larger than needed image, use less AA, and then downsize it. [QUOTE]

it absolutely and most certainly is not.

mocaw
11-01-2006, 10:07 PM
it absolutely and most certainly is not.[/QUOTE]

Well I must admit that I put my foot in my mouth- and spoke out of assumption when using another package for such things (which does work very differently!). Sorry about that...can't argue with a toon shader master!

Goes and crawls back into cave...

kimaldis
11-02-2006, 07:29 AM
:-)

Basically, setting min and max sample levels to the same value stops any adaptive sampling and you get the exact equivalent of rendering at higher res and sampling down, but without the hassle.

It's also probably that rendering to higher res yourself will lead to a slower render. There's always a bit of samplling overlap at tile boundaries. Higher resolution = more tiles = more overlapped sampling = slower rendering.

http://www.lamrug.org/resources/samplestips.html

for a good rundown on how mental ray anti-aliasing works. *everybody* should know this llike it's second nature. Unfortunately few do and there are many misconceptions out there.

kimaldis
11-02-2006, 07:30 AM
Kim has some great videos on the softimage site about Toon shading and ink lines. Definitely worth watching.

The toon stuff is mostly Todd Akita's, he's the toon master. Mine are more general.

Sbowling
11-02-2006, 08:07 AM
The toon stuff is mostly Todd Akita's, he's the toon master. Mine are more general.

Sorry. :eek: I don't know why, but I always think that you did those videos for some reason. I remember that last time I tried to find those videos I was looking through all the _KA_ videos and couldn't find them. Maybe it's just dyslexia because I should be looking for the ones that start AK.

Oh well, they should really download all the videos on the SI website. They're all good. :thumbsup:

mocaw
11-02-2006, 06:22 PM
Yeah, sorry again about the ill informed post as to rendering at higher resolutions and then scaling down- I was thinking of when I used to do similar work in LW using the native, and unreal toon shaders. It would make sense that XSI would behave differently since the renders (mr/native LW) as far as I know work differently (now classic camera mode). Though the LW was FAR more simplistic, it and the unreal shader, were at least 4 to 10 times faster than the native XSI one (maybe more)- but, they were extreamly limited though too! The unreal shader had horrible AA- so I would render at twice the needed size and there wasn't a huge render time hit. I'm talking about double NTSC with four passes of AA taking about 8-16 seconds on one machine in a "semi-complex" scene.

I much prefere the look and abilities of the native XSI shader set though and have found that using even just the setting stated in the XSI guide gives me fairly reasonable rendertimes and a good image in most cases.

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