Mental Ray 3.6 - More details...


Hmm, I can’t get the framebuffer shaders in a file from 8.5 to render in 2008 at all. :sad:


Ok you’re right, it’s clipping. Babysteps I suppose. . . . :shrug: Haven’t tried the ‘contrast all’ yet, it’s on the list, but clipped buffers is a pain. I’ll report it if they can’t give me a solution.


Any news from this clipping issue?


It’s possible Autodesk will patch up the version of Maya with a newer build like 3.6.something. They have released different builds before, but nothing concrete or announced. And if that is released it would be something where you could download it from the Old Platinum deal (Gold now I think) but not get shipped a new disc I don’t think, etc. As for a workaround, I don’t see a good one and I am about to enter into production. :sad:


If nobody still reported to Autodesk about bug with clamping, I could do it.
What bug? How reproduce it?


Just follow the directions. As issues are reported it pushes the error up the list to get fixed. Same thing with features. . .majority rules.


A workaround is render as hdr file, problem with that is that u can’t have an alpha in your image, can be annoying but manageable.

Glad to see u here Pavel, to reproduce the bug easy : Render a Floating Point file, and see if its not clamped. Exr and Tiff32 are broken currently.


Just Posted The Defect Form. Hope They Will Repair This Issue Fast.


All works fine with iff, tiff and exr, but only with ‘Maya Batch’. ‘Render View’ always clamp image. Really it’s not big problem, because you may always use ‘Maya Batch’ instead of ‘Render View’.
But nevertheless looks like it’s bug.

I have logged a case.


So I can render out 32bit passes with exr if I use batch and not render view? I would like to use passes, but was planning on waiting with looking into using them till the problem with 32bit and clamping was fixed. It this is working with batch then I should start figureing out how passes work.


I just checked it, there should be a big emphasize that its only happening with the mentalrayUserBuffer system in Maya 2008, isnt it? The newly introduced output pass system seems to be broken or half baked; the internal framebuffers seem to be alright, there’s probably only short data written to them. Couldnt check it with other 3rd party framebuffer stuff yet though (like yours, Puppet ;)).


Oh yeah forget to precise, i was speaking about the framebuffers currently.

Here are parts of the .MI file when i export it :

[i]options “miDefaultOptions”
object space
desaturate off
colorclip raw
premultiply on
dither on
gamma 1.
acceleration bsp
bsp size 10
bsp depth 40
task size 0
contrast 0.05 0.05 0.05 0.05
samples -1 1
filter clip mitchell 4. 4.
jitter 0.
samplelock on
scanline on
trace on
trace depth 1 6 7
shadow segments
shadowmap on
shadowmap rebuild off
“shadowmap pixel samples” 3
caustic off
globillum off
finalgather on
finalgather accuracy view 64 35. 35.
finalgather scale 1. 1. 1. 1.
finalgather secondary scale 1. 1. 1. 1.
finalgather rebuild on
finalgather filter 0
finalgather falloff 0. 0.
finalgather trace depth 1 6 0 7
finalgather presample density 4.
“finalgather mode” “multiframe”
“finalgather points” 24
finalgather file “default.fgmap”
lens on
volume on
geometry on
displace on
displace presample on
output on
merge on
autovolume on
hair on
pass on
face both
“motion factor” 1.
“maya filter size” 0.0001
“maya reflect blur limit” 1
“maya refract blur limit” 1
“maya render pass” 0
“maya shader filter” on
“maya shader glow” on
“maya shadow limit” 6
frame buffer 0 “+rgb”
frame buffer 1 “+rgb_fp”
frame buffer 2 “+rgb_fp”
frame buffer 3 “+rgb_fp”
frame buffer 4 “+rgb_fp”
frame buffer 5 “+rgb_fp”
frame buffer 6 “+rgb_fp”
frame buffer 7 “+rgb”
frame buffer 8 “+rgb”
frame buffer 9 “+rgb”
frame buffer 10 “+rgb”
frame buffer 11 “+rgb”
frame buffer 12 “+rgb”
frame buffer 13 “+rgb_fp”
frame buffer 14 “+rgb_fp”
frame buffer 15 “+rgb_fp”
frame buffer 16 “+rgb”

state “maya_state” (
“passAlphaThrough” off,
“passDepthThrough” off,
“passLabelThrough” off,
“glowColorBuffer” 17
data “miDefaultOptions:data”
end options

camera “perspShape”
output “+rgba_fp,fb16” = “shaderGlow1:perspShape”
# Diffuse_mentalrayOutputPass
output “fb1” “exr” “images_tmp/Render_04_2008.0100_Diffuse.exr”
# Epidermal_Scatter_mentalrayOutputPass
output “fb2” “exr” “images_tmp/Render_04_2008.0100_Epidermal_Scatter.exr”
# Subdermal_Scatter_mentalrayOutputPass
output “fb3” “exr” “images_tmp/Render_04_2008.0100_Subdermal_Scatter.exr”
# Back_Scatter_mentalrayOutputPass
output “fb4” “exr” “images_tmp/Render_04_2008.0100_Back_Scatter.exr”
# Glossy_mentalrayOutputPass
output “fb5” “exr” “images_tmp/Render_04_2008.0100_Glossy.exr”
# Specular_mentalrayOutputPass
output “fb6” “exr” “images_tmp/Render_04_2008.0100_Specular.exr”
# Occlusion_mentalrayOutputPass
output “fb13” “exr” “images_tmp/Render_04_2008.0100_Occlusion.exr”
# Normal_mentalrayOutputPass
output “fb14” “exr” “images_tmp/Render_04_2008.0100_Normal.exr”
output “+rgba_fp” “exr” “images_tmp/Render_04_2008.0100.exr”

resolution 1920 1080
aspect 1.777
aperture 1.41732
frame 100 100.
clip 1. 200.
focal 2.95275
lens = “mia_exposure_simple”
environment = “Environment_mip_rayswitch”
end camera


Hi Thomas,

can I see an excerpt of the output window too. ie. the options part.



Hey Thomas
would you be so kind to show us how we can actually get the passes out from MR buffer and how to set it up

           thanks in advance :)


Hi max! Yeah i’ll post this monday, it’s a scene from my workplace, so i don’t have it here.

Yup hoy, i’m currently changing flat so i can’t do it this weekend, but monday ill post a sample scene :slight_smile:

                 As I can see Maya native shaders ready for passes. Just view mayabase.mi. Maya's shaders split out many passes like mia_material, but no way to store it to buffers. And no additional outputs(from shaders) in Maya gui.

Yes, I am aware, the structs are all in place:



declare shader
struct {
color “outColor”,
color “outGlowColor”,
color “outMatteOpacity”,
color “outTransparency”,
# BRDF components.
color “outAmbient”,
color “outIncandescence”,
color “outIrradiance”,
color “outDiffuseShadowed”,
color “outDiffuseNoShadow”,
color “outShadow”,
color “outSpecularShadowed”,
color “outSpecularNoShadow”,
color “outReflection”,
color “outRefraction”,
color “outScatter”,
color “outOpacity”

but no way to generate those and the custom ones except if there is a way with some dynamic attributes… I wouldn’t be surprised if there is, I know the “style”…

Is there someone that knows how to output passes from these native maya shaders?


I’m not getting floating point framebuffers with anything other than EXR right now. Fair enough. . .I’ll live but geez. :rolleyes:


Does it mean that Maya 2008 can render .dds format under mental ray or any renderers? I use maya 8 now but it can’t render .dds format at all.


That typically means mental ray only. I don’t think Autodesk has future plans for the Maya Software renderer.


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