Photometric lights - I'm a dummy...

[Ken Walton]

Hey everyone,

 

I've spent no time at all using Max's radiosity for two reasons - 1) I'm used to finalRender and I like it and 2) I have no idea how to set up the photometric lights.

 

What little I think I know about setting a radiosity scene is: the scene has to be accurate in scale (1:1) and that you have to use photometric lights. So I try a test - I create a 16 foot by 16 foot by 10 foot room and then place four {Photmetric Lights>Presets>Recessed 75W Lamps} in my scene (I'm basically trying to set up my office.) Now, are these presets really "Pre-Set?" because when I turn on radiosity & log. exp. control (all with default values) I get a dark scene with four dim highlights on the floor. I'm sure there are a few simple steps I'm missing, but I'm clueless. Somebody please help the idiot...

 

Thanks in advance,

Ken Walton

[Devin Johnston]

Make sure you have run the radiosity solution, once that is done you have to pick an exposure control. Logarithmic exposure control is the best one to use especially for animations. Once you've chosen this you have to play with the brightness and contrast settings. You will probably find that your materials are very saturated or over exposed; you need to adjust the material color usually making it darker than what you would see in the material editor. It's going to take some trial and error.

[Jim Mann]

Originally posted by Ken Walton:

I create a 16 foot by 16 foot by 10 foot room and then place four {Photmetric Lights>Presets>Recessed 75W Lamps

75W what? Tungsten will give you a different value to metal halide will give you a different value to sodium, will give you a different valuie to halogon etc. Try setting a value for the lamps based on lumens i.e. 2000lm. You can sometimes find lumen or candela values for lamps in manufacturers catalogues. I swear by the Erco catalogue.

 

Hope this helps...and oh yeah, as mentioned above, don't forget to process the radiosity solution before rendering.

 

JM