MAYA - VRAY // Reflection RGB

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VRAY // environnement variable

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utilize the threads on systems with more then 64 but if want to no reset affinity thread VRAY_USE_THREAD_AFFINITY=0

limit the number of threads that V-Ray uses VRAY_NUM_THREADS

VRAY // Diffuse pass not flat color

Sometimes the Diffuse RE of V-ray is not full flat colors but has some sort of shading/fresnel.
That is normal as it's the Diffuse Filter RE and is affected by reflections. To have full flat colors on compositing do the following :
Diffuse RE divided by the invert of the Reflection Filter RE
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Maya / Vray _ random color for all objects

"- add extra vray attributes to a samplerInfo node (this will expose additional outputs to the samplerInfo)
- connect the samplerInfo.vrayRndomByID to a ramp's vCoord (if you're using a vRamp) OR uCoord (for a uRamp) | or both, if you intend to switch between ramp modes
--> the ramp's position and color values will be the range of colors to be distributed to the objects
--> plug the ramp into a shader and use the same shader on lots of objects"

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VRAY/Nuke _ motion blur velocity pass

http://docs.sharktacos.com/misc.php?action=help&hid=33

MAYA / VRAY / MEL _ viewport snapshot in Vray VFB

// Vray VFB viewport snapshot
// create it in maya's renderview then load it in Vray VFB
global proc VrayVFBsnapshot () 
{
 // create snapashot from current viewport camera 
 RenderViewWindow; // open renderview
 string $panel = `getPanel -wf`;
 string $camera = `modelEditor -q -camera $panel`;
 renderWindowRenderCamera snapshot renderView $camera; // create snapshot

 // get path to TMP image
 string $workspaceDir = `workspace -q -fullName`;
 string $imageDir = `workspace -q -fileRuleEntry "images"`;
 string $imagePath =  $workspaceDir  + "/" + $imageDir +  "/" + "TMP_snapshot";
 print $imagePath;
 sysFile -delete ($imagePath+".jpg"); // delete previous snapshot -- Windows
 setAttr "defaultRenderGlobals.imageFormat" 8; // set maya software to .jpg to save it as a jpg
 renderWindowSaveImageCallback "renderView" $imagePath ""; // save snapashot to .jpg file

 // open image in vray vfb
 vrayShowVFB; // open Vray VFB
 vray vfbControl -loadimage ($imagePath+".jpg");
}

MAYA / VRay _ sprite texture pixelated

If sprite particles get pixelated with Vray (when they scale) :
Vray -> Global Option ->  Materials -> uncheck texture filter map

MAYA / VRAY _ wave with distanceTex node

To procedurally create wave near object :

- create a VRayDistanceTex, a ramp and a shader.

- add object to distTex_set

- set the ramp like below.

- connect VRayDistanceTex.outColorR to ramp.Vcoord

- connect ramp to shader diffuse.

As it's heavy to calculate, it's better to bake it to a texture file map before rendering a long animation.

NUKE / VRAY _ get 3d camera in nuke with vray exr pass

http://polygonspixelsandpaint.tumblr.com/post/40175774250

MAYA/VRAY/PYTHON _ fallof - occlusion shader

create a fallof and occlusion shader for Vray using python

#____________ FALLOF ____________#
def shFallof():
 # gamma node 
 cmds.shadingNode('gammaCorrect',asUtility=True, n='GammaTemp')
 cmds.setAttr('GammaTemp.gammaX', 0.455)
 cmds.setAttr('GammaTemp.gammaY', 0.455)
 cmds.setAttr('GammaTemp.gammaZ', 0.455)

 #Creates Ramp
 cmds.shadingNode('ramp', asTexture=True, n='facingRampTemp')
 # Remove middle color of ramp
 cmds.removeMultiInstance( 'facingRampTemp.colorEntryList[1]', b=True )
 #Modify Ramp
 cmds.setAttr('facingRampTemp.colorEntryList[2].color', 0,0,0, type='double3' )
 cmds.setAttr('facingRampTemp.colorEntryList[0].color', 1,1,1, type='double3' )
 cmds.setAttr('facingRampTemp.colorEntryList[2].position', 1)
 cmds.setAttr('facingRampTemp.interpolation', 1)

 #Creates Sampler Info node
 cmds.shadingNode('samplerInfo', asUtility=True, n='facingSamplerTemp')

 #Connects Ramp and Sampler
 cmds.connectAttr('facingSamplerTemp.facingRatio', 'facingRampTemp.vCoord', f=True)
 cmds.connectAttr('facingRampTemp.outColor', 'GammaTemp.value', f=True)

 # connect it to a surface shader
 cmds.shadingNode('surfaceShader', asShader=True, n='SH_TMP_Fallof')
 cmds.connectAttr('GammaTemp.outValue', 'SH_TMP_Fallof.outColor', f=True)

 # Select Ramp
 cmds.select('facingRampTemp', r=True)

 #Renames nodes so you can use the script as many times as you want
 cmds.rename('facingRampTemp', 'facingRamp_F')
 cmds.rename('facingSamplerTemp', 'facingSampler_F')
 cmds.rename('SH_TMP_Fallof', 'SH_Fallof')
 cmds.rename('GammaTemp', 'gammaCorrect_F') 

shFallof()


#____________ OCCLU ____________#
def shOcclu():
 # surface shader
 cmds.shadingNode('surfaceShader', asShader=True, n='SH_TMP_Occlu')
 cmds.shadingNode('VRayDirt', asShader=True, n='VrayDirt_TMP')
 cmds.connectAttr('VrayDirt_TMP.outColor', 'SH_TMP_Occlu.outColor', f=True)

 #Renames nodes so you can use the script as many times as you want
 cmds.rename('SH_TMP_Occlu', 'SH_Occlu')
 cmds.rename('VrayDirt_TMP', 'VrayDirt_O')

shOcclu()

MAYA/VRAY _ linear workflow

Render and VFB settings

For texture map add a Vray texture input gamma attribute

Create a standard gray shader : Vray MTL with gamma correct node in diffuse, 0.5 value color and gamma value 0.455