Sun problems

[Blake Middleton]

I'm using the Viz trial and have come up with a couple of questions. First, I created just a test scene to experiment with a few things. I added some lights from the Erco website, and rendered with radiosity @ 85% quality. See below for the results:

 

So far so good, looks ok. Then I added sunlight and whoa, it blows out the whole image:

 

Its just the default sunlight settings, and looks about the same if I turn the skylight off. Is there a way to tone down the intensity of the sunlight?

 

Also, I have a carpet material on the floor with a UVW map. I can see it in the viewport, but when I render the scene, no carpet. What's going on? I've used Max for a while, and I've never had trouble with a material not showing up. Thanks.

[Eric]

Just a quick reply before I head out of the office for the weekend. Make sure in your radiosity setup, you have Daylight turned on, Exterior turned off, and your Physical Scale set to the value of your brightest light source, which in your case will be the sunlight, somewhere probably over 90,000. Logarithmic Exposure will probably give good results. Also, enable Global Subdivision in your radiosity setup. The more subdivision (lower the number) the more refined your shadows will look. A quick way to test the subdivision setting is to select an object, and modify it with a "subdivide" modifier, and drop the number. Probably want the mesh to be divided up into approximately 3-5 inch sections (triangles). I always use 85%, with refine set to 15, and filtering set to 2. Don't know why, other than I saw someone else was using the same settings and I figured I'd give it a try because I didn't know what I was doing. I still don't, but I think the above info should help. Post some more pics of your progress with settings when you get everything ironed out.

 

Eric

[proces2]

looks like you need to play around with the Exposure Control settings.

 

Set the Controls to Logarithmic (should be that way by default) - make sure daylight is checked (not exterior) and play with the brightness value until you get what you are looking for.

 

this isn't fool proof, so it will take trial and error to get it jsut right.

 

sean

[proces2]

to save a bit of time, and to just figure out the lighting first - i might dial down the settings that Eric has suggested.

 

65% initial quality should be good enough - all the light actually gets cast within the first 10% ro something - anything after that is just refinement.

 

set refine iterations to 5.

 

start with filtering at 1. you can adjust this setting and see the results right in your viewport. it blurs the shadowing to make it appear smoother. beyond 3, it begins to wash the shadows away.

 

yes - use global subdivision. for this scene, start at around 10".

 

once you get renderings that show the lighting how you want - then i would start to increase the quality, decrease the mesh size, etc.

 

sean

[abicalho]

Just to clarify the two checkboxes at the Exposure Control: Daylight and Exterior. They only make a difference when both are ON. If either one is off, their effect is off.

 

We made them both a single checkbox in future versions.

 

Alexander

[vizwhiz]

hi There

 

Alex

 

where and when are These "future versions" ?? coming out?

 

hopefully the entire Radiosity and Lighting setup has been re-visited, re-vamped and re-vised

 

will This actually work This Next Time around (more user-friendly)??

 

is There anyway to PUT ALL of the useful knobs, bells and whistles and checkboxes relating to Lighting and Radiosity Interior/Exterior into ONE COHERENT system or dialog box ??

 

idle curiousity

 

Thanks

 

Randy

[abicalho]

Future versions of the Radiosity Engine, which include 3dsmax 5, or anything that comes after that (which I have no idea of).

 

Alexander

[Blake Middleton]

Thanks for everyone's help. You have really helped me out. Here is a litle update:

Here are my settings:

Initial Quality: 65% (which is greyed and I can't change)

Refine Iterations: 15

Filter: 1

Global Subdivision: Enabled

Meshing Size: 4

 

Logarithmic Exposure Constrol

Brightness: 85

Contrast: 50

Mid-tones: 1

Physical Scale: 90000

Daylight & Exterior Checked

 

As you can see there are still a few issues, most notably the splotches and the dark corners. Also, it looks as if the lights have been turned off, they have no affect at all, yet I have not changed them. Thanks.

 

[ November 25, 2002, 07:54 AM: Message edited by: Blake Middleton ]

[Blake Middleton]

Here's another:

I upped the filter to 5, and it helped with the splotchiness. I also upped the lights to like 750% and they are now showing up. Overall, looking better, I think.