Hi everyone, I am using OpenSCAD to generate a 2-dimensional vector that I wish to treat as a heightmap. If I had the data in a file, I could load it using 'surface' and to produce exactly what I want, because surface fills in the areas between the height points to produce a continuous form. How do I do the same thing directly from my vector? I feel that there must be a way but today I am not seeing it, short of processing the vector to construct a polyhedron ... surely there must be an easier way? Thanks, Steve

pts = [
    [0,    0,    -sz.z],
    [nx-1, 0,    -sz.z],
    [nx-1, ny-1, -sz.z],
    [0,    ny-1, -sz.z],
    for (x = [0:nx-1])
        for (y = [0:ny-1])
            [ x, y, a[x][y] ]
];
faces = [
    [ corners+0, corners+1, corners+2 ],
    [ corners+0, corners+2, corners+3 ],
    [
        each for (x=[0:nx-1]) dataIndex(x,0),
        corners+1,
        corners+0,
    ],
    [
        each for (y=[0:ny-1]) dataIndex(nx-1,y),
        corners+2,
        corners+1,
    ],
    [
        each for (x=[nx-1:-1:0]) dataIndex(x,ny-1),
        corners+3,
        corners+2,
    ],
    [
        each for (y=[ny-1:-1:0]) dataIndex(0,y),
        corners+0,
        corners+3,
    ],
    each for (x=[0:nx-2], y=[0:ny-2])
        if (rands(0,1,1)[0]>0.5) [
            [ dataIndex(x+1, y), dataIndex(x, y), dataIndex(x, y+1) ],
            [ dataIndex(x+1, y+1), dataIndex(x+1, y), dataIndex(x, y+1) ],
        ] else [
            [ dataIndex(x+1, y), dataIndex(x, y), dataIndex(x+1, y+1) ],
            [ dataIndex(x+1, y+1), dataIndex(x, y), dataIndex(x, y+1) ],
        ],
];
scale([sz.x/(nx-1),sz.y/(ny-1),1])
    polyhedron(pts, faces);

On 2/14/2024 9:47 AM, Steve Lelievre via Discuss wrote: > Hi everyone, > > I am using OpenSCAD to generate a 2-dimensional vector that I wish to > treat as a heightmap. If I had the data in a file, I could load it > using 'surface' and to produce exactly what I want, because surface > fills in the areas between the height points to produce a continuous > form. > > How do I do the same thing directly from my vector? > > I feel that there must be a way but today I am not seeing it, short of > processing the vector to construct a polyhedron ... surely there must > be an easier way? Right now, it's "process the vector to produce a polyhedron".  I tried a bit to extend surface() to process arrays, but ran into some data-representation problems and haven't gotten back to it. Here's a module I wrote a while back.  Call it like "sfc([[0,2,1],[2,1,0],[1,2,2]], [10,10,1]);" The randomness toward the end is to break up visual patterns that form if each cell is always triangulated in the same direction.  The size parameter controls the X and Y size, and the Z size of the "base". module sfc(a, sz) { function dataIndex(x, y) = dataBase + x*ny + y; nx = len(a); ny = len(a[0]); corners = 0; dataBase = corners + 4; pts = [ [0, 0, -sz.z], [nx-1, 0, -sz.z], [nx-1, ny-1, -sz.z], [0, ny-1, -sz.z], for (x = [0:nx-1]) for (y = [0:ny-1]) [ x, y, a[x][y] ] ]; faces = [ [ corners+0, corners+1, corners+2 ], [ corners+0, corners+2, corners+3 ], [ each for (x=[0:nx-1]) dataIndex(x,0), corners+1, corners+0, ], [ each for (y=[0:ny-1]) dataIndex(nx-1,y), corners+2, corners+1, ], [ each for (x=[nx-1:-1:0]) dataIndex(x,ny-1), corners+3, corners+2, ], [ each for (y=[ny-1:-1:0]) dataIndex(0,y), corners+0, corners+3, ], each for (x=[0:nx-2], y=[0:ny-2]) if (rands(0,1,1)[0]>0.5) [ [ dataIndex(x+1, y), dataIndex(x, y), dataIndex(x, y+1) ], [ dataIndex(x+1, y+1), dataIndex(x+1, y), dataIndex(x, y+1) ], ] else [ [ dataIndex(x+1, y), dataIndex(x, y), dataIndex(x+1, y+1) ], [ dataIndex(x+1, y+1), dataIndex(x, y), dataIndex(x, y+1) ], ], ]; scale([sz.x/(nx-1),sz.y/(ny-1),1]) polyhedron(pts, faces); }

Thanks, that is useful. Steve On 2024-02-14 10:25 a.m., Jordan Brown wrote: > Right now, it's "process the vector to produce a polyhedron".  I tried > a bit to extend surface() to process arrays, but ran into some > data-representation problems and haven't gotten back to it. > > Here's a module I wrote a while back.