As the program performs lighting calculations, the view updates at regular intervals to reflect calculations up to that point. You can change the interval at which the view refreshes by increasing or decreasing the number of steps between visual updates.
To change the refresh rate during radiosity calculations:
Select View
> 3DTrueView > 3DTrueView Options, or click the 3DTrueView
Options button on the 3DTrueView toolbar.
In the Program Settings dialog, select the Rendering tab.
Edit the value in the Change Display Every _ Steps edit box. Fewer steps increase the frequency of visual updates, but can increase rendering time.
Click OK.