Vertex lighting in Blitz3d?

Community Forums/Developer Stations/Vertex lighting in Blitz3d?

Happy Sammy(Posted 2006) [#1]
Hi all,

Have you tried "Vertex lighting" in Blitz3d?
Is it better than lightmaps?
Are there any info.?

Thanks in advance
Sammy
:)


Mustang(Posted 2006) [#2]
Vertex lighting can be used sometimes instead of lightmaps but you have understand the pros and cons... vertex lighting can catch the light ONLY at vertex position and it blends the value between vertices, So if you have a long rectangle wall with four vertices and say a tree in the middle you won't see any tree shadow on the wall because there isn't any vertices on that spot on the wall.

So basically you need a very dense and evenly spaced mesh to get vertex lighting look good (as a "lightmap"). Vertex coloring of course uses less (well, none) texturemaps but usually I wouldn't even try to replace lightmaps with vertex colors.


Happy Sammy(Posted 2006) [#3]
Hi Mustang,

Thank you.
Will FPS be increased if we use Vertex lighting,
instead of using lightmaps?

Sammy
:)


Gabriel(Posted 2006) [#4]
Will FPS be increased if we use Vertex lighting,
instead of using lightmaps?


No, quite the opposite if you use it instead of lightmaps. As Mustang already explained, you'd have to subdivide your meshes, making more polys and more polys means less FPS.

What you save is videoram because you're not using textures.

The key is to use BOTH lightmaps and vertex colors, and find a balance between them so that you use lightmaps where you have well-spaced vertices and you use vertex colors on geometry which already has densely packed vertices. Find a good balance between not using too many textures for lightmaps and not needlessly subdividing too many meshes for vertex colors and you're home and hosed.


Happy Sammy(Posted 2006) [#5]
Hi Mustang and Gabriel,

Thank you for your reply.

@Gabrial: You said "balance". Do you mean that we could apply vertex lighting to some parts of whole scene and
lightmaps for remaining parts to get this balance?

Thanks in advance
Sammy
:)


Gabriel(Posted 2006) [#6]
@Gabrial: You said "balance". Do you mean that we could apply vertex lighting to some parts of whole scene and
lightmaps for remaining parts to get this balance?

Yes, that's exactly what I mean.