Are all light sources in VRay mutually exlusive?

[snivlem]

Hi,

I've noticed when using Mesh lights if I type a value of 3200 lumens, then switch back to the Multiplier value, the multiplier value updates itself - all the values seem to be tied together and this is good!

My problem is that I have a carpark scene at the moment with 200 flat planes in it. I've turned these into mesh lights and set them to a value of 3200 lumens,
I then changed it back to Multiplier mode and it gave me a value of 64000.

I wanted this 6400 value because I believe that VRayLightMtl as a material is faster to render and I don't want to use something arbitrary...so I applied the VRayLightMtl to my planes and deleted the mesh light nodes. Upon doing a test render with 64000 (as a multiplier) for my lights with direct illumination, they are now nuclear white.

So it seems that multiplier value is different between a VRayMeshLight and a VrayLightMtl (with direct illumination on)?

Is there maybe a formula to use between the two to get similar values?

Edit: maybe the best way to put what I'm asking is can you get physical values out of VRayLightMtl?

[ivaylo.ivanov]

VrayLightMtl with direct illumination is translated directly to VRayMeshLight. If your color and multiplier match, you will get exactly the same light intensity. The default color for the light material is grey, so you must change that.