basic sdf_utils module, converts output of generate() to verts/tris (np, python modes) (#4094)

* add file * add description * newline

basic sdf_utils module, converts output of generate() to verts/tris (np, python modes) (#4094)
* add file * add description * newline
74bfa4b3 · Dealga McArdle · GitHub · 1830d118 · 74bfa4b3
--- a/utils/modules/sdf_utils.py
+++ b/utils/modules/sdf_utils.py
+import numpy as np
+
+def geometry_from_points(points, mode="python"):
+    """
+    using sdf module from:  https://github.com/fogleman/sdf
+
+    input:
+        points: the direct output from `f.generate()`
+        mode:   "np" (numpy), or "python"
+    output:
+        geom:   with a `.verts` atribute and `.tris`
+                verts and tris are output in numpy arrays if the mode is "np",
+                else standard python lists.
+
+    usage in snlite:
+
+        '''
+        in scale v
+        out verts v
+        out faces s
+        '''
+
+        from sdf import *
+        from sverchok.utils.modules.sdf_utils import geometry_from_points
+
+        f = box(2) & slab(z0=-0.5, z1=0.5).k(0.1)
+        f.scale((1, 0.5, 1))
+        f -= cylinder(0.25).circular_array(6, 0.6).k(0.05)
+
+        points = f.generate(samples=23200)
+
+        geom = geometry_from_points(points, mode="np")
+        verts.append(geom.verts)
+        faces.append(geom.tris)
+
+    """
+
+
+    geom = lambda: None
+    num_points = len(points)
+    if mode == "python":
+        geom.verts = [plist.tolist() for plist in points]
+        geom.tris = np.arange(0, num_points, 1).reshape((-1, 3)).tolist()
+    elif mode == "np":
+        geom.verts = np.array(points)
+        geom.tris = np.arange(0, num_points, 1).reshape((-1, 3))
+    return geom