Lightbulb question for Skitchy

Community Forums/Developer Stations/Lightbulb question for Skitchy

MadJack(Posted 2003) [#1]

Am checking out Lightbulb for lightmapping my Tank Universal levels and it looks pretty good!

A question. I've been using one single DX light above my level to act as 'the sun', but I've also 2 distant dx lights positioned below and off to the (opposite) sides of my levels to give an illusion of a more textured diffuse/ambient/reflected lighting on polys not directly illuminated by the sun. I'd like to recreate these 'below ground' lights in lightbulb. My question is, can I set these up in Lightbulb so that they are included in the lightmapping but do not cast shadows on the geometry?

Second question: I've been using Lightwave to create my levels. A level usually contains corridors that are open to the sky. The level walls are single sided polygons (i.e not mapletty kind of solid shapes) whose normals point into the corridor. In an open corridor, the sun will hit the back of the walls, yet should cast shadows in to the corridor. Will this cause lightbulb problems? (And what about very large single polygons?)

jhocking(Posted 2003) [#2]
1 - I don't think you can turn shadow casting on/off for lights.

2 - I'm not sure I understand the question exactly but it sounds like you are asking if lights will be blocked by backfacing polygons (ie. polygons facing away,) in which case I don't think so.

MadJack(Posted 2003) [#3]

I've since had the time to play around with lightbulb a bit more (I'm trying to work out a good workflow from Lightwave's modeler -> Decorator -> Lightbulb -> B3d) and that appears to be true (but would be a useful feature I think).

2 - 'blocked by backfacing polygons'. Yep, and you're right, they won't cast shadows which means I think I'll have to alter my modelling style to create walls as solid blocks with backing polygons to get shadowing.

Skitchy(Posted 2003) [#4]
1) Yes, you can turn off shadow casting BUT not for individual lights. You can stop any MESH casting a shadow by including the flag "lb_noshadow" in UserFlag1. Check the Manual -> Reference section near the top (I think).

2) J is right. You'll need to add the 'backfaces' in your modeller.

3) Very large single polygons are not a problem - there's actually a setting in there to deal with them (PreScale). I use VERY large scale geometry myself and LightBulb just loves it! Just make sure you don't set the LumelSize too low, and increase PreScale if you experience 'artifacts' in the lightmap.

Hope that helps you make your decision :)

jhocking(Posted 2003) [#5]
A little off-topic, but do you think PreScale might help the minor problem I was experiencing earlier with exporting to b3d? I never mentioned but that level was pretty large scale geometry.

Skitchy(Posted 2003) [#6]
Yes, definitely. PreScale is there for exactly that purpose. All it does is scale the entire scene down by the given factor - but this helps to eliminate glitches due to large numbers in the lightmapper.

MadJack(Posted 2003) [#7]

I'm having issues with LB export to B3d. I've left a note in the LB support forum which you may have already seen?

I'm at work at present and can't log on to that forum.

Skitchy(Posted 2003) [#8]
I've answered it over there :)