First, before raising the gain control (which is a boost and has the limitation of all boost controls), you should adjust the balance of ambient-sunlight more (or completely) towards the ambience. Then, you have to play with the amount of ambient light in the material editor for each material involved. This is the control that lets you individually fine tune the responsiveness of each material to the radiosity engine. After you have set all that, if the result isn't still what you want, you can adjust the - skydome lighting gain (if your interior has open windows) - gain value - bias value in SMALL quantities (the gain excursion is too much). Especially the bias color is very sensitive, a gray color that is even slightly lighter than black will have a great influence. Radiosity in Vue 5 has several parameters, not as many as you would find in a professional application, but many enough to require careful adjustment. As a rule of thumb, use this (it is valid for all similar situations): if you have, say, 5 parameters that can influence a result, and your aim is to obtain "10", you will always get a better and more balanced result by distributing the 10 over all five parameters (e.g. setting all five parameters to "2") than by setting only one parameter to "10" with all the others left at "0". Hope this helps. If you like to share the scene, I will set up parameters for you with which to have a better result.