Lighting Problems - Seams & Shadows (+ Pix)

Adam Linden said General was the best forum, so here it is. I love the new lighting, but have come accross some problem when building, and dunno if there is a fix in the works, or if there is a way around them. Basically I am finding that when Face 0 of a cube is lit, it creates an x like shadow on the surface, which doesn't match the rest of the walls. Also... once in awhile, even when all the prims and faces are facing the same direction, a prim or two will shine considerably brighter, revealing the seems of a wall.

Picture 1 shows all the problems I am talking about. Every texture is a blank texture, and they are all the same color. I think this might be a bug LL needs to address.

http://img153.imageshack.us/img153/7236/lighting13kl.jpg

Picture 2 focuses more on the X problem regarding lighting Face 0. This may be a problem we have to live with

http://img153.imageshack.us/img153/7184/lighting23us.jpg

Picture 3 just shows how messy it is. All same colors and blank texture. Middle hollow prim is Face 0. Others are all Face 4.

http://img20.imageshack.us/img20/1720/lighting34nj.jpg

I want to know if anyone else is experiencing similar problems, what you might suggest to avoid this (I want to use lighting! hehe) - and if you think it's something that needs to be reviewed by the Lindens and possibly fixed?

Prims can only be lighted in a few ways.

Maybe the light is not reaching the edge of your prims due to falloff ;0

I think the "x" pattern you're seeing is the effect of SL's "vertex lighting." A vertex is a point of a polygon (triangle). All prims in SL are made of polygons, connected at their vertices.

SL only calculates light values at the vertices and then interpolates (fudges) the light across the rest of a polygon.

A flat wall is actually made of four polygons with connected vertices. You're seeing the light being fudged.

It doesn't look as good as per-pixel lighting, but it looks better (in most cases) than the per-face lighting we used to have.

Yeah. it's not a bug. It's just a side effect.

But if you take the prim/wall section in the centre of your window (Pic 3) and stretch it so it's the same height as the surrounding wall, then you'll see that it blends in much better. But you'll then need to adjust its depth to avoid the flashing texture problem.

No, it wouldnt stop that quick and make that obvious of a line.

I now understand about the X problem...but still don't understand the other problem.

ive also have a couple of issues with lighting.

1. If i make a sphere and turn it into a light, raise it high in a room centre, it has a nice soft effect. Move it slightly to the left or right and the emitted light all but disappears. Move it back and its bright again.

The light that hits the room seems to "snap" on a grid.

2. General flicker coming from lights when i move around.

it is normal, cut it out