How to turn off Radiosity???

[Aaron]

I am using Viz 4. My opinion of it changes on a daily basis. I am attempting to do an Architecture exterior rendering using the daylight system. I do not wish to calculate a radiosity solution. I simply want to use a direct light to cast my shadows and a skylight to lighten up the shadows. The problem I am running in to is as follows.

 

I create my geometry and map materials onto it.

I then add a daylight system and thats where I run into a problem where the skylight is too dark. So I up the multiplier on the skylight. However, I do not see a difference even when I set the multiplier to an enormous value. Recently, I discovered that if the radiosity option in the radiosity panel is set to: the skylight multiplier does seem to affect the rendering. After discovering this I thought things were going to work better now that I seem to have control over my lights. Well, not exactly, Everytime I render, the Radiosity panel resets itself to use VIZ radiosity and of course my skylight again has no affect on my render. I do not understand what is going on? It seems the radiosity and the exposure control dialogs have a mind of their own. What am I doing wrong? Again, I only have the daylight system using the IES sun and IES skylight. Furthermore, the exposure is set to logarithmic (exterior option is checked). The rendering dialog has the "use radiosity" option unselected.

 

Any assistance would greatly be appreciated.

Thank you

Aaron

[wda]

AARON,

 

I just ran through the same set of problems. I took and made a simple scene solids and so forth, on a plane. Then systematicaly, turned all lights radiostity off. Worked with the environment exposure controls. This I felt was key, it's like the f stops in photography, too much light no contrast, too little light scene is too dark. Then I, one by one started to play with the settings lighting & radiosity. If it looks like a light is not showing up, put it to a bright green high stauration. This gave me a feel for how the light was being distributed and working with in the scene.

 

I'm sure there are other specific solutions and techniques. If you have the time, building an understanding of the controls from the ground up is the way to go, I think.

 

Up load & Post a render, or screen shot of the scene. It will help others see what the problems are.

 

Hope this helps get you going.

 

brgrds

WDA

[Aaron]

I found that if you turn off cast shadows on the skylight you can count on more predictable results. Thanks for your reply.

[ZepSOFD]

Aaron,

 

In the rad. dialog box leave "VIZ Radiosity" on and uncheck "Use Radiosity" and "Compute Radiosity when Required" in the render dialog box. Then set the skylight multiplier to 1 then render, adjust Exposure Control, Skylight multiplier as needed, oh and uncheck exterior you will not need it just run the brightness down instead. Remember though that Skylight without Radiosity is a direct "Rays per Sample" calculation so it will be quite a bit slower then using it with Radiosity or a standard light skydome.

 

edit/ I also forgot to mention you may have to lock the ambient to diffuse to get the skylight to work on non-bitmapped materials.

 

Skylight only

/edit

 

tom

 

[ July 28, 2003, 06:50 PM: Message edited by: ZepSOFD ]