Lightmapping - texture bleeding ???

Hello.

I´m trying to develope a lightmapping system, mainly for learning purpose, a just-for-fun-project.

But now there is one problem i just cannot solve:

A mesh gets lightmapped, the maps are displayed, the textures seem to fit - but the lightmaps seem to bleed.

I´ve read all i could find (blitzbasic.com-forum, blitzcoder-forum, other graphics-boards,...) about this problem, but none of my wannabe-solutions fixed the problem.

Maybe somebody of the b3d-masters can help me out?

The code to create a lightmap image and setup of texture coords:

Function create_lightmap(meshobj,size#,lmsize#,cset=0)
fnt=LoadFont("arial",10)
SetFont fnt

	
	For sys.lmsystem=Each lmsystem
		tricount=sys\tris
	Next
	
	mapw#=tricount*size
	maph#=size

	x#=0
	y#=0
	
	lm=CreateTexture(lmsize,lmsize,512)
	SetBuffer TextureBuffer(lm) 
	
	For tri.triangle=Each triangle
		DebugLog "Tri: "+t+" X:"+x
		CopyRect(0,0,size,size,x,y,TextureBuffer(tri\lightmap),TextureBuffer(lm))

;**********************************
;right here seems to be the problem
	
	For vert=0 To 2
			u#=((tri\pu[vert] * (size /lmsize) )+(x/lmsize))
			v#=((tri\pv[vert] * (size / lmsize) )+(y/lmsize))
			DebugLog "VERTEX "+tri\vert[vert]+" Texturcoord: "+u*mapw+" "+v*maph+" - "+tri\pu[vert]+" "+tri\pv[vert]
			 VertexTexCoords(tri\surface,tri\vert[vert],u,v,1,cset)

;*********************************
		Next
		;Color 255,255,255
		;Rect x,y,size,size,0 	


		DebugLog ""
		x=x+size
		t=t+1
	Next
	
	SetBuffer BackBuffer()
	
	TextureCoords lm,cset
	TextureBlend(lm,3)
	EntityTexture(meshobj,lm,0,cset)
	
	mapimage=CreateImage(mapw+20,maph+20)
	CopyRect(0,0,mapw+20,maph+20,0,0,TextureBuffer(lm),ImageBuffer(mapimage))
	Return(lm)
End Function

It´s just the code, working (with bleeding), erased my attempts - better to read...


Screenshot:


Any help would really be appreciated.

Cy