thanks for answer
in 3ds max its good in uv ] and has no problem in rendering !
what should i do ?
My guess is the areas with issues the surfaces are so close together, they are basically being considered as intersecting to lightmass. If you can “thicken the cloth” or widen the space between those areas, the issues should go away.
I’ve seen those kind of artifacts when there is no lightmap coverage… maybe your lightmap uvs are overlapping or outside of the given space?
…ok I try again! …just lost my first try :S
So I’ve realized that you’ve uploaded the object! 
And the problem is that your mesh has a duplicated element!
I removed it and tried to fix the mesh… it’s not ideal!
Single sided… and difficult to make a proper lightmap… What I was trying isOh yeah! Your lightmap was also “not good”! I guess it was autogenerated… :S It had seams all over… :S
So this is my “end” result…
thanks for solving the problem
my lightmap was created by steamroller in 3ds max
also maya and blender does not help me
can you explain for me your unwarp method ? [manual unwraping]
Ok so this is my third try after 2 lost posst!! :S
All I did was pelt mapping! Keeping the whole surface as one island!
Can you make video or powerpoint to teach pelt mapping ?
youtube does not help me !
Well in this case it couldn’t be more simple!
Click on the mesh - uvw unwrap - open editor - select all polygons - click the skin icon under Peel - Start pelt button (wait a lot in this case to stretch it) and finally start relax button if needed! Will do the trick!
You can use the same method for other objects too (elements) that have more roundish surface…