Lighting Issue

[frozenfire2]

I"m having some lighting issue I was hoping someone could point out to me what's the issue. Been stuck on this for few hours. Anybody know why are some of the grass piece darker than some other?




Here are the details of the issues:
1) only appear after baking.
2) Material is 2 sided . Tried with and without transmission color
3) Tried different lighting, points, directional, to no avail
4) Tried getting the grass to cast shadow and NOT cast shadow. still same
5) The grass is not using lightmap. I have lightmap res set to 0. Which should force vertex lighting.
6) The pieces of poly that is dark are dark BOTH sides. While bright pieces are bright BOTH side.



it only worked if i turn off precomputated shadow. Suffice to say i'm pretty sure it had to do with static lighting

[frozenfire2]

single piece of grass mesh loosks like that.

[apophis3d]

I am thinking it has something to do with the normals on the plane. Try setting them so the normals are hard instead of soft.

[frozenfire2]

anyway there's no normal map. with the help of some memebers on UDK Central . I've managed to solve this, it's the 2sided thing. Apparently 2 sided material does not work with static lighting. I've then proceeded to make the grass have 2 face and use 1sided material. However, I'm still having issues as to being unable to light the grass from the back



the top picture is viewing from light source, see the strong contrast between shadowed and non-shadowed areas. While the bottom pic is viewing against the light source, showing a complete field of grass that's not lit. no contrast between shadow and non shadow area. THis is because the light does not touch the back face of the grass. Can anyone give me an idea as to how to make the backface of the grass lit up when the front is being lit? Transmissions do not work with static lighting as well as it further lit up the front and does nothing to the back surface after building light.

[frozenfire2]

bump .. need a solution

[chrisradsby]

No not normal map man, the normals on the poly.

http://www.polycount.com/forum/showt...55#post1149155

Check this out.

[frozenfire2]

i thoguht so too but he mentioned "Try setting them so the normals are hard instead of soft.". I'm not aware that you can 'soften' normals of a vertex. I thought they just a point at a direction. Nevermind let me read up.

edit : just read the thread. Apparently they said UDK doesn't support custom vertex normal. Is this true? if it's not, what are the ways where I can modify them.