Hello,

I think I have missing faces in my polyhedron because I am unable to compute
a difference or something similar with an other object.
However, the plain polyhedron looks fine so I don't know where my bug is
located.

Thank you very much for your help.
Andreas

lenX=100;
lenY=200;
sizeX = 100;
sizeY = 100;
lenTot=lenXlenY;
cntX=3;
cntY=5;
amplitude=10;
wallSize=3;
function generator(x,y) =
amplitudesin(x360cntX/lenX)sin(y360cntY/lenY);
function p(x,y,z) = x+ylenX+zlenXlenY;

// x1y1 x1y2 x1y3, ... , x2y1, ...
//Start 2. X Point 2
//Start 2. Y Point lenX
//Start 2. Level: lenXlenY
points = [
for(y = [0:lenY-1]) for(x = [0:lenX-1])
[xsizeX/lenX,ysizeY/lenY,generator(x,y) - wallSize/2] ,
for(y = [0:lenY-1]) for(x = [0:lenX-1])
[xsizeX/lenX,y*sizeY/lenY,generator(x,y) + wallSize/2],
];
faces = [
for(x = [0:lenX-2]) for(y = [0:lenY-2])
[p(x,y,0),p(x,y+1,0),p(x+1,y+1,0),p(x+1,y,0)],
for(x = [0:lenX-2]) for(y = [0:lenY-2])
[p(x,y,1),p(x,y+1,1),p(x+1,y+1,1),p(x+1,y,1)],
for(x = [0:lenX-2]) [p(x,0,0),p(x+1,0,0),p(x+1,0,1),p(x,0,1)],
for(x = [0:lenX-2])
[p(x,lenY-1,0),p(x+1,lenY-1,0),p(x+1,lenY-1,1),p(x,lenY-1,1)],
for(y = [0:lenY-2]) [p(0,y,0),p(0,y+1,0),p(0,y+1,1),p(0,y,1)],
for(y = [0:lenY-2])
[p(lenX-1,y,0),p(lenX-1,y+1,0),p(lenX-1,y+1,1),p(lenX-1,y,1)],

];

difference(){
polyhedron(points,faces,convexity = 20);
cube([sizeX/2,sizeY/2,wallSize*10]);
}

--
Sent from: http://forum.openscad.org/

Thank you very much for your comments.
Now I got it. I don't have missing faces - I have wrong oriented faces.
And I learned a new feature of the editor :)

Just in case someone needs something like this:

lenX=100;
lenY=200;
sizeX = 100;
sizeY = 100;
lenTot=lenXlenY;
cntX=3;
cntY=5;
amplitude=10;
wallSize=3;
function generator(x,y) =
amplitudesin(x360cntX/lenX)sin(y360cntY/lenY);
function p(x,y,z) = x+ylenX+zlenXlenY;

//for(x = [0:100])
//for(y = [0:100])
//translate([x,y,generator(x,y)])
//sphere(r=3);

// x1y1 x1y2 x1y3, ... , x2y1, ...
//Start 2. X Punkt 2
//Start 2. Y Punkt lenX
//Start 2. Ebene: lenXlenY
points = [
for(y = [0:lenY-1]) for(x = [0:lenX-1])
[xsizeX/lenX,ysizeY/lenY,generator(x,y) - wallSize/2] ,
for(y = [0:lenY-1]) for(x = [0:lenX-1])
[xsizeX/lenX,y*sizeY/lenY,generator(x,y) + wallSize/2],
];
faces = [
for(x = [0:lenX-2]) for(y = [0:lenY-2])
[p(x,y,0),p(x+1,y,0),p(x+1,y+1,0),p(x,y+1,0)],
for(x = [0:lenX-2]) for(y = [0:lenY-2])
[p(x,y,1),p(x,y+1,1),p(x+1,y+1,1),p(x+1,y,1)],
for(x = [0:lenX-2]) [p(x,0,0),p(x,0,1),p(x+1,0,1),p(x+1,0,0)],
for(x = [0:lenX-2])
[p(x,lenY-1,0),p(x+1,lenY-1,0),p(x+1,lenY-1,1),p(x,lenY-1,1)],
for(y = [0:lenY-2]) [p(0,y,0),p(0,y+1,0),p(0,y+1,1),p(0,y,1)],
for(y = [0:lenY-2])
[p(lenX-1,y,0),p(lenX-1,y,1),p(lenX-1,y+1,1),p(lenX-1,y+1,0)],

];

intersection(){
polyhedron(points,faces,convexity = 20);
translate([0,0,-1](wallSize))
cube([sizeX,sizeY,wallSize2]);
}

--
Sent from: http://forum.openscad.org/