Sunlight system in Max 5 :(

[mzagorski]

Im doing a sunlight analysis in max based on the location of Edinburgh Scotland. The following image is my results from:

 

June 21

Sunrise: 4:28am

Sunset: 22:05pm

 

Sept 21

Sunrise: 6:15am

Sunset: 7:15pm

 

Dec 21

Sunrise: 8:44am

Sunset: 3:42pm

 

 

.... the image shows from midnight -> midnight... but on Dec 21, Im not seeing the sunlight appearing until 11am.. 2 hours later than it should be although the sunlight is above the ground plane at the correct time. Is there a way to get the ambient light to show at the correct time?

 

Mike

[abicalho]

What's your Exposure Control?

 

If you're keeping the same exposure control for all the images, the ones where the sun is too dim may not show up well.

 

Alexander

[mzagorski]

Hi Alexander,

 

I used Logarithmic Exposure Control for all images. I've got an animation setup with 24 frames.. from midnight until midnight... I set the date, then render out the first 23 frames.

 

Should I be doing something different with the exposure? I am using both IES Sky and IES Sun.

 

Thanks

[abicalho]

Exposure is like the Aperture of a camera. If you keep the aperture constant, at some point, your scene will be either washed out or will be all dark.

 

Ideally, you should also animate your brightness as the sun goes up and down, so you can realistically adjust the lighting level of teh camera.

 

Alexander

[Craig Ramsay]

Sun in Edinburgh? LOL What sun??? They should build in a rain and black cloud system into max for Edinburgh

 

Craig

[rpict]

nice layout of the results. that makes sense:))

 

did you try scanline for comparison?

 

-rpict

[mzagorski]

Thanks Rpict... That was just a quick test. Its part of the site analysis for my university project. Once its finished I will probably post the final presentation on CGA if Jeff will let me. Had various help here and there from other CGA users so would be nice to show the end result. Maybe sometime after June 5th it will be ready

 

I tried scanline but it was very dark.. sun not appearing until even later. I like radiosity because it gives some ambient light around the scene early in the day.

 

Craig - Yeah.. someone needs to crank up the exposure for Scotland. Definitely too dull... although its been nice the past few weeks. Summer must be coming to an end soon.. normally only lasts for a week or two max. :gebigeek:

[rpict]

mike, aren't you a lightscape user as well?

you could set up the sun in lightscape and import it to max. you won't get the skylight, but you could investigate if there is a bug in sunlight system in max.

 

just a thought:)

 

-rpict

[Craig Ramsay]

I dont think the skylight is linked to the time, date and place in max so you are never going to get an realistic "daylight" simulation. I think the sunlight system was created to do shaddow studies, please correct me if I am wrong.

 

Craig

[kid]

I think you're right. Max might be accurate as far as shadow angles but I don't think it's 'environment' is sophisticated enough for a technical simulation of this kind.

 

Radiance is the perfect tool for this kind of study.