View Full Version : Geographically correct shadow studies in LW

12-10-2003, 04:54 PM
Howdy all you LW'avers,

I know ( well lets say Im 99% sure) that atm there is no way of getting LW to do a geographically correct shadow study for architectural purposes. Does anyone out there know of a way to do/approach this? The only way I can think of at this stage is to eye it off from other programs as in setting up a scene, see where the shadows fall & try to replicate it in LW. Any hints/pointers would be greatly welcome.

12-10-2003, 08:21 PM
are you talking about the suns position in relation to different places on the planet. If so check out sunspot in the sky tracer panels.

12-10-2003, 08:21 PM
Try using Skytracer. There is a section in there that allows you to set the Longitude and Latitude and time of day.

If used correctly it should be what you are looking for.

12-10-2003, 08:22 PM
hunter- Jinx! :P

12-10-2003, 08:24 PM

12-10-2003, 08:39 PM
... don't I feel friggin embarrased all of a suden - I have never noticed that panel - maybe because it doesn't apply to standard lights - many thanks ;)

John Fornasar
12-11-2003, 02:18 PM
When you are in SkyTracer2, click on the Suns tab, then Sun Position button. There is a preset for Sydney (I see you are down under), or, input the GPS co-ordinates for the location (here in the US, most home addresses show up in White Pages searches with latitude and longitude postions.)

Layout is set up so that the X axis runs North to South (positive X being North).

I usually make a ground plane simulating the area that I am modeling, then place a few primitives in the shape of the building I am doing and a few of the surrounding buildings. You can put a cylinder and sphere to mark out significant trees in the area. Set the time of day in SkyTracer, and compare your render shadows with those in "real life" (or those in a picture that you take on a particular day and time).

If you parent your entire scene to a null, you can rotate the entire scene to get your shadows to match. This is good when the road layout in your area doesn't run North/South/East/West. You'll be able to get an exact match this way.

One more thing, you may want to delete the default distant light... if you do, and you don't add any others, you'll get an error message when you Close the scene stating that you need at least one light in a scene... don't worry, when you reopen the scene, SkyTracer2 will put the light back in. I usually change the default light to a soft sky blue and turn down the intensity a bit for some shadow fill.

12-11-2003, 03:43 PM
Many, many thanks people ;)

John Fornasar - cheers for the great tips. Yeah I'm in Melbourne so this will be very handy indeed over my upcoming projects.

12-11-2003, 03:47 PM
Good Tips!

A Mejias
12-11-2003, 06:45 PM
WOW! Great tips!

I've been looking for a plugin to do that and never noticed it was already there. I guess I missed it, because I don't use Skytracer much anymore. I don't really like the clouds. They look like they are projected on a flat plane instead of a dome. Hope they fix that. Maybe an input for planet size and presets for the planets in our system?

John Fornasar
12-11-2003, 08:41 PM
I've been looking for a plugin to do that and never noticed it was already there. I guess I missed it, because I don't use Skytracer much anymore.

You don't have to use SkyTracer... select your Distant Light, hit the (Items) (Motions) Motion Options button and select Sun Spot from the Add Modifier drop-down list. It's the same panel that appears in SkyTracer. You can then use your own backdrop or dome.