misss tests

[dragonP]

try adjusting your radius in the eperdermal subdermal or back looks like it not high enough. Great pic though. oh ya dont use amibent lights in your scene they create really dark spots when rendered.

[murnau]

what do you think of my shader? some advice?
thanks

[Pickman]

Hey DragonP, I’m on SSS here, so no subdermal parameter. I don’t get rid of the undersampling,or if I do so lose a great amount of the shading capabilities, it seems whatever the light the sampling goes crazy according to the light. I tried on flat or rund objects and got the same problem, perhaps master zap could comment on that
I don’t get it, maybe my object is too complex.
It seems the distribution is jumping somewhere…

Hum.

[murnau]

please, someone help me!!! :banghead:

[dragonP]

hey pickman,

Maybe its your normals on your object, have you tried seeing if your normals are the problem MR SSS fast skin works by calculating the normals on your surface, with a complex object like that it could be the normals. :shrug:

My best bet is to ask Master Zap, again or post your maya file to him.

Well Good Luck.

[murnau]

hey Pickman, how much time do you spend to render displacement with SSS? maybe I’ve a low ram but with me all these procedures are veeery long and sometimes I have to close maya

[Pickman]

Hey Murnau, I wasn"t rendering a 2048*2048K map as I would with zbrush extracted maps, there were three nodes (bulges) to displace the plane. rendering took about 3 minutes on a P4 2.2, 2 gig of ram, crappy graphic card. No final gather or GI, this is pure maya light (4 or 5) don’t remember. I can send you the file as soon as I sort the undersampling out if you like.

Hope someone can give me an explanation. Maybe Master Zap, if he’s around.

DragonP, thx for your support mate, unfortunately I rendered the displacement on a plane which had no normals issues, the displacement may be affecting the normals, but I doubt it. It seems to come from the light attenuation.
By the way, coming from 3dsmax how do you make far or near attenuation with maya lights ???
I didn’t find out.

[murnau]

but I can use the displacement effect and SSS together? do you know some tutorial about it?

[floze]

DragonP, thx for your support mate, unfortunately I rendered the displacement on a plane which had no normals issues, the displacement may be affecting the normals, but I doubt it. It seems to come from the light attenuation.
By the way, coming from 3dsmax how do you make far or near attenuation with maya lights ???
I didn’t find out.

Does the plane have any actual thickness? If the sss cant find any backfaces, it behaves strangely. Test your displacement on a sphere, or try extruding the plane.
For your second question, do a search in the maya help on ‘light decay’, .

[Pickman]

Hey Floze, good to have you around, that’s a good idea, I tried the fast SSS simple on characters and spheres without too much troubles, but the plane was badly rendered, I’ll definately try it tonight and let you know.

Second problem, I can’t seem to render out bump with the threee displacement node I connected to the mib color node, plus the extra node for the bump, have you ever tried it Floze, displacement and bump within the mib color node ?

About the light decay, this is cool, only sems to work on spotlight though, but that will do :-))

[CoolioNewbie]

I’ve been following this guide: http://www.highend3d.com/maya/tutorials/misss/ (its great btw) Trying to learn a little about Misss_fast_simple_maya shader

But im having problems with it: "API 0.0 error 301095: while defining texture “SSk”: redefinition of texture “swatch::SSk”

SSk is my mentalrayTexture1 node just renamed, tried to save it in different places (same place where my scene file is, right in C:, lots of different places. Diff. names too.

second problem is:
Then when I press the number 3 button (output connection) nothing happens :
http://www.highend3d.com/maya/tutorials/misss/misss_images/sg_navigate.jpg

I’m sorry if this has been answered before but I cant seem to work it out.

[delarge]

hey folks.
the same error happens here when I try to render multiple objects with seperate misss_fast_skin shaders attached to them. evey object has it’s own shadernetwork and write-lightmap-node. so there should be no conflict. rendering results are also altering in a way that randomly the lightmap generation fails on the different objects.

…The second part of the image, shows the head using satellite rendering. I got this error :

     PHEN 4.1  error: misss_lightmap_create: Lightmapping attempted on slave, not supported. Aborting lightmap.
     

 ...

any idea on this?

thank you...

[Pickman]

Hey Delarge, have you written the lightmaps one by one or in one go ? I noticed I had problem generated my lightmaps one by one, so I generated all the lightmaps first then did the shading network afterwards. That might be your problem.

[murnau]

CoolioNewbie, maybe i can help you.
When Jozvex says output connection is refered to the hypershade, so you have to go in the hypershade and click on the button for input and output connection (a little square with two arrows) then you finally arrive to the MR options

In addition, I’ve modified my misss shader, now tell me if I’ve to improve the illumination or what? To have a more realistic figure what I’ve to add?
This scene is composed by: misss_fast_skin shader, 2 spot lights, HDRI, final gather

(I don’t like it!! )

[Ash-Man]

I figured it out. (With the help of Floze’s helpful comments above) Hooked the sss shader up to surface shader sg (and the light map to the sg too) and the hooked the light intensity to the ‘overall color’ value in the sss shader and finally had to apply the inverse of that to the surface shaders out transparency value. Works a treat. take a look:

can you provide us with a simple digram of that workflow
or simple file
thanks

[system]

search the thread or follow links to the tutorials on various pages, the workflow has been explained at least 5 times in the thread before 20 pages.

[vzap]

Hi all!

Great thread! And great work! I’ve seen the misss_fast shaders for over a year without really paying attention, until I found Jozvex’s tutorial (thanks for that), and I’m now a happy man. This is the best SSS hack I’ve ever seen!

I do have a question though, which I think hasn’t really been asked here. What about transparency? I realize that transparency and this shader’s logic are kind of incompatible, since you need front and back surfaces at all times, but here’s the situation. I showed a colleague of mine this shader and he loved it, and is now using it for his plants and leaves. Thing is, he’s got roughly modelled leaves, translucence looks great, but he’d now like to add detail to the leave edges with a transparency map, which totally makes sense. So the idea is to shade the whole model with a misss_fast shader and then pipe that into a surface shader’s color and map it’s transparency. Sounds simple, yet I haven’t managed to do that yet… Actually everytime I tried maya crashed! I figured a maya surface shader wouldn’t do the job because it’s a maya shader and not a mr custom shader, and doesn’t pipe into the mr attributes of the SG. But it didn’t work either using mr surface shaders… Any idea how to achieve that?

Now here’s a little hint I can contribute with. When rendering on a windows workstation, leaving the file name blank in the mr texture node works fine, and the light maps are rendering in-ram. But when rendering on a linux renderfarm that doesn’t work! Apparently on linux light maps NEED to be written to disk, for some obscure reason. Problem is, network paths don’t seem to work, so you can’t write out your light maps to the actual project on the network, so it needs to be written locally to a temp directory. Solution is to use something like /usr/tmp/mySuperbSSStexture, as that local directory exists on every linux box. Problem is, obviously that doesn’t work on your windows machine, so you need to leave the file name field blank as long as you’re tweaking your shading, and only add the /usr/tmp thing just before sending to the renderfarm. Everything then works perfectly. Other thing, already mentioned I think but… scene optimization and “delete unused” delete all mr texture nodes, so be careful with those…

Cheers,

  Vania

[floze]

I do have a question though, which I think hasn’t really been asked here. What about transparency? I realize that transparency and this shader’s logic are kind of incompatible, since you need front and back surfaces at all times, but here’s the situation. I showed a colleague of mine this shader and he loved it, and is now using it for his plants and leaves. Thing is, he’s got roughly modelled leaves, translucence looks great, but he’d now like to add detail to the leave edges with a transparency map, which totally makes sense. So the idea is to shade the whole model with a misss_fast shader and then pipe that into a surface shader’s color and map it’s transparency. Sounds simple, yet I haven’t managed to do that yet… Actually everytime I tried maya crashed! I figured a maya surface shader wouldn’t do the job because it’s a maya shader and not a mr custom shader, and doesn’t pipe into the mr attributes of the SG. But it didn’t work either using mr surface shaders… Any idea how to achieve that?

If you really want to use a maya surface shader in the mr slot, turn on ‘Export with Shading Engine’. Otherwise, simply leave the surface shader in it’s place (the maya shaders slot), and plug the misss into it as you would do with any shader/texture; be sure to leave the mental ray slot in the SG blank though. The lightmap shader needs to be assigned to the shading group which is assigned to your specific objects. In dubio, assign it to any shading group that might be this one.

Btw: Maya crashes, because it doesnt expect multiple outputs (a struct) from the shader in the mental ray slot. This is particularly important if combining maya shaders with mental ray shaders within a phenomenon - which is basically no problem at all.

[Timefly]

does anyone know how to make miSSS (or other custom shaders?) respect maya lightsources “emit specular” being turned off ?

right now having to resort to a workaround using a mix8 with the sss as base…and screening 1 or several maya blinns over to have the lights specular properties read correct.

thanks

T-Fly

[Nando3D]

Hi

When i render with misss_fast shaders Mental ray, it looks ok but when i try to upload the iff image to Combustion the model with the shader (misss_fast shaders) is not there (not alpha, not color, info) any other model with different shader is ok (phong , lamberth)

simple scene eg: Plane (Phong), Cube (SSS), final render ok in maya , import to Combustion the image is only the plane with a black cube in the middle…

Any ideas…

Thanks