Light through Alpha not casting correct shadows
polycounter lvl 11
I'm still a bit new to UDK. So much info and settings it is overwhelming.
I've tried looking for a solution but can't seem to find one.
The problem is Lighting. I'm casting a light through a static mesh which has an alpha, basically light coming through a window. But the alpha isn't casting shadows correctly.
Things I've tried:
-I have second UV sets for light maps
-They dont overlap, etc
-I have the light map set up high 1024
-its double sided (obviously)
-the texture is a 1024 tga with alpha (should be enough res in that!)
-light SFQ is high
here are some pics. not sure what other information you need.
Oh, I'm also getting light 'bleeding' out at the bottom of the wall. I've checked the static mesh and it defintely intersects the floor, so theres no gap. Is there anyway to stop this?
I've tried looking for a solution but can't seem to find one.
The problem is Lighting. I'm casting a light through a static mesh which has an alpha, basically light coming through a window. But the alpha isn't casting shadows correctly.
Things I've tried:
-I have second UV sets for light maps
-They dont overlap, etc
-I have the light map set up high 1024
-its double sided (obviously)
-the texture is a 1024 tga with alpha (should be enough res in that!)
-light SFQ is high
here are some pics. not sure what other information you need.
Oh, I'm also getting light 'bleeding' out at the bottom of the wall. I've checked the static mesh and it defintely intersects the floor, so theres no gap. Is there anyway to stop this?
Replies
1. i had to actually create a second face on the backside. the "Two Sided" setting just wasnt working for me so i put 2 faces almost on top of each other and that got the general alpha going.
2. if you are using a bsp for your floor (it looks like it), hit f5 on the surface and lower the lightmap resolution to something like 2 4 or 8 (1 or 2 will give best results)
But to get that kind of detail in your shadows, you'll need a huge lightmap.
Translucent materials can cast shadows.
http://udn.epicgames.com/Three/Lightmass.html#Translucent%20shadows
I ended up using a static mesh floor and upping the lightmap res on that.
Two sided seems to work ok for me, didn't need to create second faces.
You're right about the lightmap resolution having to be stupidly high though!
Is there anyway to blur the shadow's edges so I don't see the aliasing so badly?
I will try the modulate/modulate better next
Well, the setting name is almost the same as in Maya then. Select your dominant directional light, go to it's properties, and there under light component (or something similar) should be a tab called "lightmass". In there should be a setting called "light source angle". Increase that to get blurrier shadows.