8

Animation with Radiosity 59
6.
In the Interactive Tools group of the Radiosity
Processing rollout, click Setup to display the
Environment panel (page 3–268) ,whereyou
set exposure controls.
7. When working with non-physically based
lights, always use the
Logarithmic Exposure
Cont rol (p age 3–293)
.OntheLogarithmic
Exposure Control rollout, select Affect Indirec t
Only.Thiswillcausetheexposurecontrolto
affect only the results of the radiosity solution.
By doing so, you will maintain the way your
direct lights render without radiosity. Use
the Brightness and Contrast controls of the
exposure control to adjust the intensity of the
radiosity solution to match the lighting at an
appropriate level.
Tip: You can use the thumbnail preview to adjust
brightness and contrast interactively.
8. Click Render Scene to render the scene
after radiosity processing.
Summar y
The following table will help you obtain good
results with radiosity.
Physically Based
Workfl ow
Non Physically
Based Workflow
Lights Photometric Lights
(page 2–1155 )
Standard Lights
(page 2–1142)
Daylight IES Sun (page
2–1163)
and IES
Sky (page 2–1165)
Directional Light
(page 2–1145)
and Skylig ht (page
2–1149)
Exposure
Control
Any
Logarithm ic (p age
3–293)
turn on
Affect Indirect Only.
Units
Make sure your
scene is set to the
appropriate scale.
Make sure your
scene is set to the
appropriate scale.
Animation with Radiosity
By default, a radiosity solution (page 3–50)
is calculated at the current frame. If you are
animating objects and you want to per form a
radiosity solution at every frame, select Compute
Advanced Lighting When Required in the
Render Scene dialog > Render panel >
Common
Parameters rollout (page 3–27)
>Advanced
Lighting group.
Once the renderer starts processing each frame
of your animation, the radiosity solution will be
computed for each frame as required. This occurs,
forexample,whenanobjectmoves,oralight
intensity changes. If nothing changes in the scene
from one frame to the next, the radiosity engine
will not recalculate the solution.
Note: Due to t he random statistical sampling used
by the radiosity engine, there might be some
flicker ing between f rames. If this occurs, increase
the va lue of Initial Quality or the number of Refine
Iterations to solve the problem.
Tip: Before launching a lengthy animation with
radiosity, you should process a radiosit y solution
manuallyforasingleframetomakesurethe
results are acceptable.
Tip: If you animate only your camera (as in
an architectural walkthrough) then you can
calculate a radiosity solution for only the first
frame of the animation, and reuse it in all
subsequently rendered frames by tur ning off
Compute Advanced Lighting When Required on
the Common P arameters rollout of the Render
Scene dialog.
Avoid using the
Automatic Exposure Control
(page 3–291)
for animations. This exposure
control can change from frame to frame, creating
aflickeringeffect.