Vray Ambient Light

[bradon]

is there an equivalent to this workflow in Vray?

http://mentalraytips.blogspot.com/20...-ambience.html

the idea is to use AO node or Dirt node to fake ambient bounce lighting in scene. I don't see the equivalent lens shader options in Vray rect lights.

[LarsSonparsson]

Cant you use texture in rect light? You could put vray dirt map there and it will work as AO. You can even set the AO mode to EnvOcclusion to get the colour from your HDR, Sky or what ever you are using in environment.

Not sure can you do that in Maya so easily. I'm Max user.

[Morbid Angel]

yes its already supported in vray. Just create a maya ambient light and plugin vray dirt into its color.

[bradon]

yes its already supported in vray. Just create a maya ambient light and plugin vray dirt into its color.

It looks like it works pretty close, however maya's ambient lights are weird. even though they emit only ambience they seem to localize the light at the XYZ pos of the light.

I never really got it working properly with an ambient light in maya with mental ray either.

With zap's second method in maya using an area light seems to work much better. because the scene seems to get lit very evenly from a true ambient light.

area light with AO as light shader mental ray
http://i245.photobucket.com/albums/g...reaLightMR.png

ambient light with AO plugged into color in mental ray
http://i245.photobucket.com/albums/g...entLightMR.png

ambient light with vray dirt into color in vray
http://i245.photobucket.com/albums/g...ightVray-1.png

scene file
http://www.paraportable.net/files/AmbientLightTest.zip

you can see the same thing is happening in mr as in vray where the light seems like its casting brighter around the origin of the ambient light, which isn't exactly what you would expect.

[Morbid Angel]

Well for that case you may use the light plugin. If you go to create/vray/create from vray plugin/light/ you can select lightAmbientMax. If you connect your occlusion to that it renders fine.

[DrDardis]

It looks like it works pretty close, however maya's ambient lights are weird. even though they emit only ambience they seem to localize the light at the XYZ pos of the light.

there is a slider attribute in the ambient light called "ambientShade". if this is set to >0, it acts as a point light blend. set to 1.0, it is a pure pointlight. Make sure this is attribute is set to 0.0

NB. Disable "use ratrace shadows" on this light as well

Hope that helps.