Excellent renders are possible - getting the lighting right

[Allan Chesney]

I am very impressed with the realistic results that are possible using Radiosity and Raytrace (See images below) but you have to get the light settings right to achieve it.  Balancing the interior and exterior lights (if you have a window in the view) is the issue and my experiments indicate this involves reducing the interior light wattage drastically.

In the images below the interor lights have been kept lower to accentuate the sunlight through the window. 
The setting used are as follows:

Overall Settings
   Advanced Radioisty  - Quality setting Level 5.
   Overall Brightness -1.75 (to reduce the sun brightness otherwise the outside was washed out)
   Antialias 4
   Daylight enabled

Interior Lights.
   Ceiling light on right 20W (100W incandescent at Scale of 20/100)
   Ceiling light on left 15W (100W incandescent at Scale of 15/100)
      Shades on these lamps set to 85% transparent, 3% Emissive
   Stand Lamp 10W (100W incandescent at Scale of 10/100)
      Shade 90% transparent, 4% emissive

Transparency on the lamp shade obviously makes them look like glass (or fabric).
Emissive setting makes them glow so they appear to be a light.

Some of the settings are hard to find as they are buried very deep so I will post some directions images under their own headings to show how to get to them in the hope that this helps.

Allan

[mcpruitt]

Alan,

I'm glad your getting a handle on how to work with the settings.  I've been doing some of my own and am attaching here my results.  While radiosity won't complete with the sun off it will with it on.  So I have to turn down all of the lights and I don't get the best result unless I use quality 5.  My first render is with this setting.  The second is quality 3 with a few more lights.  If you see anyway to improve them let me know.

MCP

[Allan Chesney]

Mike,

They are looking very good. I have put an ehancement request in for a 'balance the sun' or 'turn down the sun' option becasue it is too hard adjusting all the lights to compensate.

The only suggestion I have is to do what I have just mentioned, reduce the sun brightness by turning down total brightness (eg -1.75 - small adjustments make big differences) - this will reduce the sunlight outside which is obviously too bright but you will have to increase interior light values. (That is a pain too - buried so deep - have put in a request on that too.)

The light under the overhead cupboard is a bit bright but if you do reduce the overall brightness and increase the other lights it will probably be about right. Thankfully I am on a few weeks leave on the opposite side of Australia (Melbourne) so I have had the time to experiment. I think I am finally getting on top of it!!  Unfortunately I still have to reboot the program however between every render, otherwise it is totally overexposed.  Having finally worked that out I was able to make some progress - until then the results were totally unpredictable.  I don't know if that is a bug or just my PC, though I think I read somewhere that someone was having similar problems.

Allan

[Doug.S]

Not sure I clearly understood this before but trying to make a good render testing with HA on or off....I found out for sure that a render of a room, camera inside, NO windows, one ceiling light....that a render with sun "off" resulted in only 55/300 radiosity completion and quality from 1, 2, or 3 were all poor.

BUT, if I turned the sun "on", then I got a full radiosity quality 300/300....but the image was too washed out so I had to turn the fluorescent  32w light down to 30% to get a good render.

Wow...so many things to be sure to check to get a decent render.

Oh yes, and I was doing an inserted photo-board "billboard" with my own image (which worked well; I had previous issues outside)....raytrace makes solid shadows but radiosity seems to make NO shadows.
But at least they both "faced" the camera