advanced rendering for AutoCAD
How many lights? I'd be happy to take a look, if you like. Zip it and use the upload link above if you're willing.
One obvious problem in the version you sent me is that the units were incorrect-- inches instead of millimeters. You can't combine natural and artificial lighting unless the units are set correctly. For the versions below I corrected the units and changed the intensity of the artificial lights to 100 watts from 220-- I did not change the texture scaling so this is wrong in mine. I also went to a standard sky with sun which is usually much faster than trying to light an interior with an HDRI and no sun. I created a multi-channel rendering and placed the lights on one channel and the sun and sky on another.
There are some minor additional things to consider when rendering:
After about two hours this is what I got-- combined, lights only, daylighting only:
Working in millimeters is just fine-- but you must make sure the drawing units in AutoCAD are millimeters. DDUNITS or INSUNITS commands will work for this.
The model is a little too big to email-- send me a private message with a dropbox or equivalent address and I'll upload my version to you. I left it running overnight:
Again, not exactly sure what you're asking.
My example used the hybrid engine, I would recommend it.
In the model you sent, you did not use light sources for the ceiling indirect cove lights. Instead, you used a material with glow. What you see in the rendering is a glossy reflection of the glowing lamp. This is not correct. Use omnidirectional source for an improved simulation, but do realize that this type of lighting will result in significant noise and can take a while to resolve.