I've got seams appearing between surfaces when using multipass rendering, how to stop this?

[Richy]

Hi,

I do a basic ambient lighting pass (but I've currently got this
returning 0.0f for no lighting), and then I re-render my scene once
for each light source. This is blended with whatever is already
onscreen. After rendering just the first light (on top of the 0.0f,
i.e. nothing) I get seams showing where surfaces join. Any ideas how
to overcome this?

My shader options are:

AlphaTestEnable=False;
AlphaBlendEnable=True;
DepthBias=0.01f;
BlendOp=Add;
SrcBlend=One;
DestBlend=One;
AlphaFunc=Always;
ZEnable=True;
ZWriteEnable=True;
ZFunc=LessEqual;

For example, see pic at http://austere3d.gallery.netspace.net.au/Unresolved/issue

Cheers,

Richy

[Ananth B.]

Hi Richy,
I use LessEqual as my DepthFunc for the first pass, and for the rest of
the passes, its Equal. The seams could be because of Z fighting.

HTH
-Ananth

Post by Richy
Hi,
I do a basic ambient lighting pass (but I've currently got this
returning 0.0f for no lighting), and then I re-render my scene once
for each light source. This is blended with whatever is already
onscreen. After rendering just the first light (on top of the 0.0f,
i.e. nothing) I get seams showing where surfaces join. Any ideas how
to overcome this?
AlphaTestEnable=False;
AlphaBlendEnable=True;
DepthBias=0.01f;
BlendOp=Add;
SrcBlend=One;
DestBlend=One;
AlphaFunc=Always;
ZEnable=True;
ZWriteEnable=True;
ZFunc=LessEqual;
For example, see pic at
http://austere3d.gallery.netspace.net.au/Unresolved/issue
Cheers,
Richy