PDA

View Full Version : infinite light problem


sketchbook
10-27-2005, 10:11 PM
i am using an infinite light as a sun object, and for some reason it's acting like a square spotlight or something. it is cutting off my objects shadow from part of my floor. doesn't make any sense.

anyone experience this?

Incarnadine
10-27-2005, 10:47 PM
I have seen this. Also with a parallel light (not a spot) depending on shadow type if I remember correctly.

Per-Anders
10-27-2005, 11:00 PM
never had this with infinite light, only with parralel light, because parallel has a starting point from where the light is, i.e. shadows only occur beyond where the light starts, unlike infinite which should always be infinitely far away from the scene. is this an old scene reloaded in to 9.5?

sketchbook
10-27-2005, 11:23 PM
yes, old scene. i could post a file.

Per-Anders
10-27-2005, 11:58 PM
and the light type isn't Parallel, it is actually set to "Infinite"? Make sure also that under "Details" "Z-Direction Only" isn't checked.

OberonX
10-28-2005, 12:10 AM
Make sure the Outer Distance in the light's Visibility tab is set to a value large enough to encompass the elements in your scene...

Incarnadine
10-28-2005, 01:11 AM
OberonX, I think that might have been what tripped me up. Thanks!

LucentDreams
10-28-2005, 06:10 AM
should only happen when using a soft shadow and the reason is because of soft shadows using a shadow map. Theres two choices an app has to handling this, seeing as how shadow maps have a specific size and quality defined by the maps pixel size.

1)the apps can automatically fit the shadow to the size of the scene, problem is if you using something lieka sphere for a sky, or have distant elements off screen and such the shadow will be much larger then it needs giving you lower qquality for uneccesary reasons

2)it can allow the user to specify a size for the shadow, this is very handy particularily if you only want to render part of a scene you can fit the shadow to that specific area optimizing the quality of the shadow. Unfortunatley it means more manual labour when using infinite lights with shadow maps.

sketchbook
10-28-2005, 06:25 AM
thanks all for the reply's. i will look into these things and get it working hopefully.

nycL45
10-28-2005, 05:24 PM
The Infinite light and inverse square falloff (details tab) have issues, too.

sketchbook
10-29-2005, 09:54 AM
i figured out that it was the "parallel width" setting in the shadow tab. bumping that up made it work, however it also changes the appearance of the shadow and makes it a little more feathered than i was needing.

Incarnadine
10-29-2005, 02:22 PM
ah, the joy of so many tweakables - the power and control over the results!
The horror of so many tweakables - bloody hell, why... what have I missed?!
(grin)

Thanks for the pointers above, I HAD missed that one myself.

MJV
10-29-2005, 08:29 PM
The Infinite light and inverse square falloff (details tab) have issues, too.

Infinite light is mainly for simulating the sun, and for such scene you would use no falloff. Also, you'll get far better results using an area shadow with infinite lights. Soft shadows are very size dependent and not suitable for scene illumination where good shadow definition is needed for lots of objects large and small all encompassed by a single light.

CGTalk Moderation
10-29-2005, 08:29 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.