Which Operations Passes

Common Render Passes and Matching Operations

Diffuse-Over
Spectacular-Screen
Rim-Screen
Reflection-Over
Ambient Occlusion-Multiply
Shadow-Over
Self Shadow-Over
Ambient Screen
Translucence or Subsurface Scatter-Screen
Fog(render in RGB)-Screen
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ao_ao - multiply
refl_reflection - screen
shd_shadow - multiply
spec_specular - screen
matte_matte used for masks(luma or alpha)
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 Merging and Blending The passes Once you Shuffle all the passes, it’s time merge them together and for this, use the Merge node and change the Operation ( Just another name for Blending mode in Photoshop ) to Plus. Except for the Refraction pass to atop.

VRayGlobalIllumination	( Change Operation to, Plus )
VRayLighting	( Change Operation to, Plus )
VRayReflection	( Change Operation to, Plus )
VRaySpecular	( Change Operation to, Plus )
VRayRefraction	( Change Operation to Plus. Or, atop )

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