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I trust in DAZ/Reality you use geometry like in 3D-Max or AGI 32 that approximates the fixture/light source, position it appropiately in the scene, and upload the IES text file for each type (group) and that represents the fixture light output?

And this overwrites whatever you do manually with the sliders?

IIRC, it only controls the light distribution, and it's up to you to supply power and efficacy for the lamp. (hence why there are inputs for that)

 

Quote - Does LuxRender automatically calculate the reflectance values of walls celiling floors, furnature and such by the materials you use? Or maybe it take the defaults (80% for walls etc) from the IES files

 

 

Diffuse/reflection color IS the reflectance value(that's literally all it is), so...yeah, basically. :P