PDA

View Full Version : infinite light and shadow map ?


seb4d
09-20-2004, 02:25 PM
Hi !

I've set up my scene with 5 infinite lights including one key light casting shadows, I used infinite lights because the character has to be lit evenly wherever he is in the scene.
I want soft shadows so I switch on Shadow Map. The problem is with Shadow Maps the image flickers a lot when animated.
I tried to play with antialiasing parameters, shadow maps resolution and sample but nothing helped.
Something I don't understand is that in the documentation it is said that shadow maps are only for spot lights, but it works for infinite lights loo...

Well, it isn't very clear, all I know is that this flickering is really annoying. Could someone give me any advice please ?

Thanks !

EdHarriss
09-20-2004, 02:37 PM
- Because shadows maps are really just projected textures they don't work well across the infininte space coverd by an infinite light.
- There just isn't enough resolution in the shadow maps to make it work properly.
- Sorry, but it is best to use spot lights for the shadows instead.

wurp
09-20-2004, 02:44 PM
Instead of using an infinite light use a spotlight placed far away from your objects, it will give you similar results and shadowmaps will work better.

seb4d
09-20-2004, 04:25 PM
Ok, thank you very much Ed for these explanations, very clear and helpfull ! :thumbsup:

Wurp I'm currently rendering a test scene with a spot light. I hope this will work.

Thanks to both of you for your help !

Jesse-Irvin
09-20-2004, 06:16 PM
You could try setting your shadow casting light to raytrace, render it out on a shadow pass and blurr it in post... *shrug* won't need to deal with moving your spot around with the character... (not that it's all that difficult to constrain a light to a model)

seb4d
09-20-2004, 06:44 PM
Yes 3d43Jesse that's what I was thinking about too, but I'm actually rendering hair and I don't get the look I want with raytrace shadows.

I'll constrain the spotlight to the character's position you're right ;)

CGTalk Moderation
01-19-2006, 08:00 AM
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.