#3DS LIGHTING
4 messages in this thread
Here is a very technical question for you guys.
We have a customer that wants as close to reality of indoor
lighting as possible. They need to know what brightnesses and positions to
put their lighting at in there building.
Are we able to set the manufactures foot candles and light
temperature color to each individual light source, and if so how? I
believe we are looking for a math formula that would convert the variables
to 3DS values… and how accurately will 3DS render the image.
If you're looking for a physically-accurate light model, the ONLY rendering
method that will suffice would be a radiosity system. There are a number
of these running on the SGI, but I don't have any names handy for you.
– G
Gary,
What we were hoping for was a best guess way to do this in 3DS
since we are hoping that in the near future versions of 3DS will far
surpass that of SGI and we wouldn't like to off toward the idea of using
SGI.
One problem with modeling accurate indoor lighting using the current
generation of 3D packages is that of diffuse inter-reflection of
surfaces. Ray tracers handle specular reflections well — they can
figure out how light bounces from shiny surface to shiny surface —
but they break down when trying to figure how non-shiny surfaces
reflect light.
If you look up at the ceiling, you'll probably see that a corner of
the ceiling is subtly darker than where the wall and ceiling meet in
the middle of the room. Fewer diffuse inter-reflections there, less
light. The same phenomenon won't show up with our current computer
light models.
Like Gary said, radiosity reproduces this phenomenon. The only PC
package I know supporting it is StrataVision on the Mac. Calculation
times are horrendous though. Some of the Amiga guys simulate
radiosity by using multiple soft point light sources, but there goes
accuracy out the window.
Would your client accept an *estimate* of light needs, instead of
decimal-point accuracy?