misss tests

#561

HI Tubbrit

I also could’nt avoid specularity with the miss_fast_simple_maya.
Solution was to assign a miss_fast_skin_maya shader.

#562

Hi, thanks for the suggestions chaps! Much appreciated, I’ll give them a full ‘workout’ tonight! :slight_smile:

#563

Things are working again, I just had to flip the normals of the model…

#564

You could try putting the color in “overall_diffuse” instead of “unscattered diffuse” and “epidermal”. Technically this is the same as if you would have set the texture to all of unscattered diffuse, epidermal, subdermal and back…

The risk you run is that dark areas may or may not show the kind of scattery look you want. Since anything dark/black in “overall” will attenuate EVERYTHING. Which isn’t always what you want. It depends, though, sometimes it is.

I have found that putting a slightly blurred veiny-fleshy texture in my subdermal layer has worked wonders for a “better look”.

You could also make a special “overall” texture which contains any specific “hard details” you really want shown.

And so on.

The shader is made to be flexible in this regard. Perhaps it is too flexible :wink: Well, I’m the guy to blame …

/Z

#565

i really like that flexibility - ounce you get the hang of which channels have what effects it gets really easy to get results quickly. i would stay away from overall color and try other stuff first.

the subdermal layer will usually effect most of the color - with that chimp head i plugged colormap into “unscattered diffuse”, “epidermal”, and “subdermal” – it works for that type of skin. for human skin you might try colomap mulitplied /divided with another color or noisemap. mix it in as needed. this isn’t human skin but i did that on this -also used painted radius maps.

when your painting color maps for human skin – most of it is subdermal stuff.

#566

these shaders are gorgeous! but i got a problem. im doing a short with a couple characters and i’m in the rendering stages now. im rendering my first shot now and i’m noticing that on certain frames it looks like the lightmap was trying to be used again from the previous frame. i apologize if this has been asked already but is there a way to force mental ray to create a new lightmap for every frame? any help would be greatly appreciated. thanks.

Los

after thumbing through some previous posts i think i found that i should use the same texture node on all my sss shaders. is this true? im getting some horrible tearing in my textures as if they were being projected on the character when the character is in a different position.

#567

It should do precicely that without you having to jump through any particular hoops.

However, what version are you running? If you are back on the good old “Siggraph '04” “Bonus Tools” version, you may indeed have this issue in some cases. If you are on Maya 6.5-ish you should not.

/Z

#568

Hey Zap!

I’m working on Maya 6.5 on a PowerMac DP 2.5 Ghz G5 with 2.5 gigs of Ram. I hope me being on a Mac isn’t a problem. I’ll try rendering it out at school if it’s supposed to work flawlessly. I’m wondering if its ok to have more than one SSS shader in the render scene at a time. I have 4 different shaders on each character. One for each eye, body, and teeth. I’m rendering each character seperately.I tried to batch render with both characters but it quits prematurely. I have a different lightmap node for each shader. I have linked 3 regular spotlights with raytraced shadows to each shader. when I go to render, the SSS works about 50% of the time. If it doesn’t work on a frame I just click the render button again and it’ll work. sometimes it takes 1 or 2 re-renders for it to show up. I tried to batch render with both characters but it quits prematurely. I hope its not a mac thing. But I’ll try it out on the PC’s tomorrow.

Here’s a link to the render

http://members.dslextreme.com/users/bizdizzle/ssstest2.mov

Thanks for your help

#569

That looked really odd.

like very very increadibly really odd.

I wonder if it could have something to do with motion blur? Are you using rapid-scanline motion blur… or?

Are you rendering multiple frames simultaneously which may be writing to the same lightmap files? Are you using files or the “no filename necessary” trick?

Look at it this way, I rendered this without any such effects… hmm…

/Z

#570

Hey Master Zap!

I just installed the new Mac OS Tiger on my computer and reeinstalled all my applications. I started up a batch render and so far everything is looking good. I’m keeping my fingers crossed though. Thanks for your response and that demo is awesome as are the shaders. Thanks for everything.

Los

#571

I’m still getting a little trouble with the animation. I don’t think it’s the depth map anymore. I think it has to do with my lighting setup. It’s just a simple 3 spotlight setup the standard fill, key, and backlight. I’m wondering if I should use more lights? I don’t want to use final gather or any kind of global illumination. I am thinking about pluging in the ambient occlusion shader into the overall color slot though. What kind of lighting setup did you use for that demo with the “Hulk”? I’ve got about 1500 frames to render so I want to keep it fast and simple. And I need it to be done within the next 3 weeks. It should be plenty of time unless it’s gonna take 30 mins. a frame. Any suggestions would be greatly appreciated. Thanks again.

I’m thinking it might be the motion blur. You said something about rapid scanline motion blur? Should I be using that? I’m just using Exact (Deformation) with default settings. It looks like the SSS effect “breaks” during fast motions.

#572

If it’s caused by the motionblur, I’d did it without any and add the blur in post by using motionvectors. That’s way more flexible anyway.

#573

Hey Floze!

I’m not sure how I would do that post blur. I’ve heard of plugins like Reel Smart motion blur and all that but I don’t have it. There isn’t a way to do that with plain old After Effects is there? I’ll try rendering it out without motion blur and see if that helps. I’ll forgive that “strobe” look for that SSS look. But it may be my lighting setup. There might not be enough lights in my scene to give the SSS shader the info it needs. Thanks for the suggestion Floze.

Los

#574

There’s a recent thread going on about right that problem:

You might ask mimo, as he also seems to be an osx user. Good luck! :thumbsup:

#575

Hey guys,

Yep, It’s all about the motion blur. I’m going to have to shut it off. I still love the shader Master Zap. I’m probably doing something wrong. Thanks for the help.

Los

#576

Wierd. I have had no problems with motion blur. Are you using motion blur for the shadows as well? This almost looks like a shadow motion blur problem. Or as if shadow maps were left over for earlier frames.

Are you using shadow maps? Or raytraced shadows?

On the hulk I used 3 point lights w. raytraced shadows, plus the ambient occlusion shader plugged into the “ambient” slots of the material and the lightmap with a mere 16 samples.

I used “rapid scanline” motion blur, which you will probably find in mental ray 3.4 under the new named “new rasterizer” or something.

Unfortunately I don’t know exactly where in Maya’s UI this option may be…

EDIT: Asking some smart people that know yeilded:


render globals> mental ray> raytracing> scanline, 
'on' is the default, you switch to 'rapid'.
 
then turn on motion blur in:
 
render globals> mental ray> motion blur

/Z

#577

Hi Guys,

I’m using multiple textures for a character I’m working on with misss, but if I assign misss to a group of faces, and a different misss to another, and so forth, the shader turns all dark. I even tried to get the shaders to use the same lightmap, but it didn’t work. It only seemed to work if I assigned the misss to the entire object.

So the problem then becomes that I can’t assign multiple textures, so I then opted to use multiple uvsets, which works, BUT I then have the problem that multiple uvsets don’t work with multiple bumps in Maya. THe bump only works in the default uvset, which is a problem again because it effects all my uvsets.

So what should I do?

-Dilber

#578

This problem was discussed earlier in the thread. This thread has an abundance of answers to a lot of questions, searching the thread is usually a good idea before posting questions that have already been discussed and answered. Good luck.

#579

Thanks Bill,

I hope I didn’t come across as looking for a quick fix. Searching through this thread helped me initially to get the misss to work for me. More specifically connecting the lmap to the shader groups when using mix8 and also changing the Light Linking Mode.

Having said that, the answer I was looking for was in a previous thread, but I didn’t understand it at the time. With my limited experience with Mental Ray, I didn’t realize that you could actually connect lights in the shader, until a friend pointed it out to me just now. Here I thought manually connecting lights ment using Maya’s light linking.

-Dilber

#580

Not a problem, happy SSS’ng =)