Exterior Shadow Progression Study

[MegaPixel]

http://www.hobson-eds.com/DaylightStudy1.zip

 

The above link is a small 600k DivX Encoded movie of my first shot at this.

 

I'd like to know if anyone else here has bothered to animate a Daylight System yet for a Shadow Progression Study. Obviously, there is alot more to a good looking Study then just animating the "hour" value. You have to consider the change in Sunlight color as it approaches and leaves the horizon as well as ambient Skylight intensity and color as Night gives way to Day. In this particular scene, I didn't have a landscape so I used a plane and animated the color of a standard material to go from Black to white and then back again.

 

I'd like to know how others would do a study like this and what steps they would take to make an eye poping difference.

 

Also, I'm questioning the precision of the Daylight System and I may be wrong on this. According to this movie, the Sun seems to set two hours earlier then it does in real life based on the time, date and location I have set. The Movie starts at 4:22 am and ends at 7:22pm. If I adjust for Daylight Savings, I could get an hour closer however I live in a part of the States which does not observe Daylight Savings

 

Notes:

-This is a Light Traced Animation using Logarithmic Exposure Control throughout. I think you can compensate for the overly dark morning and evening frames by animating the Skylight multiplier (Something I didn't do but will try next time).

-I'm thinking that when the Sun is horizontal (Dark and no shadows), the skylight should be an extra blue color to simulate moonlight and just bright enough to make out the shape of the house but nothing more (Something else I didn't do but will try next time).

 

 

Anyhow, I would appreciate any thoughts and suggestions. Thanks guys, Megapixel orangeshy

 

[ July 15, 2003, 02:20 PM: Message edited by: MegaPixel ]

[abicalho]

Hi MegaPixel,

 

When you choose the city in the list, is the TimeZone setting correct? You seem to be in Eastern Time, so is it correctly showing -5? I guess it maybe showing -6 because you're a little bit too east to be in the -5 timezone, and there the "imaginary line" is a bit off.

The Daylight system does a "best guess" for where the Timezone will be. In some cases, where the lines we draw move too far from where they should be, the guess will be invalid.

 

Let me know if that's your issue. Else let me know your city and what timezone it should be and I'll look into it.

 

Thanks,

 

Alexander

[MegaPixel]

Thanks for the reply Alexander.

 

The City I choose was Lafayette, Indiana and the Timezone shows up as -6. This part of Indiana is on Central Time currently however because it doesn't observe Daylight Savings Time, it will be on Eastern Standard Time in the Fall. (Off the record, I don't see what Daylight savings time is any good for anyhow. These guys get along just fine without it).

 

Anyhow, I can click the Adjust for daylight savings box and that will throw sunrise and sunset forward 1 hour which, like I mentioned earlier, will get me a litle closer to reality but I don't want to do that if it is technically inaccurate - See what I mean?

 

What are your thoughts? - Mega

[abicalho]

The correct Timezones for the US are:

 

East = -5

Central = -6

Mountains = -7

Pacific = -8

 

If you're on East Timezone (regardless of Daylight savings), the Timezone thing should be -5, and not -6. That's the "guess" error I mentioned on the first post.

And since you're not in Daylight Savings, you should not enable the checkbox either.

 

With -5 and no Daylight, are you still seeing differences?

 

Let me know and I'll check it when I get to the office.

 

Alexander

[abicalho]

Hi again,

 

I did a small test. I created a Daylight system and chose Lafayette, IN. I then disabled Daylight Savings and corrected the Timezone to EST (-5).

Setting the date for Today, my approximate Sunrise and Sunset were: 5:35am and 8:11pm.

Weather.com lists both as 5:31am and 8:16pm which I would consider a good approximation.

 

Let me know if you can get similar results.

 

Alexander

[recon]

Originally posted by MegaPixel:

Anyhow, I would appreciate any thoughts and suggestions. Thanks guys, Megapixel orangeshy [/QB]

As far as suggestions for this type of project,

Our friend "swami*" wrote a little script for another friend of mine a few months ago that automatically places date, day and time into a max text object. The text changes dynamically with the animation of the sunlight object... so you can render a time stamp right on the image:)

 

As far as accuracy goes, I wonder if it would make a difference to type in the exact Lat/Long coordinates rather than choosing the city? Maybe weather.com and the sunlight system are using slightly different data.

 

-john manning