Allow use of a two-dimensional pitch in Path2D.rasterize

tests/test_raster.py

@@ -34,8 +34,17 @@ def test_rasterize(self):
                            fill=True,
                            width=2.0)
 
+        # rasterize with two-dimensional pitch
+        pitch = p.extents / 600
+        filled_2dpitch = p.rasterize(origin=origin,
+                                     pitch=pitch,
+                                     resolution=resolution,
+                                     fill=True,
+                                     width=None)
+
         # count the number of filled pixels
         fill_cnt = g.np.array(filled).sum()
+        fill_2dpitch_cnt = g.np.array(filled_2dpitch).sum()
         both_cnt = g.np.array(both).sum()
         outl_cnt = g.np.array(outline).sum()
 
@@ -45,6 +54,8 @@ def test_rasterize(self):
         assert both_cnt > outl_cnt
         # filled+outline should have more than filled
         assert both_cnt > fill_cnt
+        # A different pitch results in a different image
+        assert fill_2dpitch_cnt != fill_cnt
 
 
 if __name__ == '__main__':

trimesh/path/path.py

@@ -1045,7 +1045,7 @@ def rasterize(self,
 
         Parameters
         ------------
-        pitch:      float, length in model space of a pixel edge
+        pitch:      float or (2,) float, length(s) in model space of pixel edges
         origin:     (2,) float, origin position in model space
         resolution: (2,) int, resolution in pixel space
         fill:       bool, if True will return closed regions as filled

trimesh/path/raster.py

@@ -33,8 +33,8 @@ def rasterize(path,
     ------------
     path : Path2D
       Original geometry
-    pitch : float
-      Length in model space of a pixel edge
+    pitch : float or (2,) float
+      Length(s) in model space of pixel edges
     origin : (2,) float
       Origin position in model space
     resolution : (2,) int
@@ -51,7 +51,7 @@ def rasterize(path,
     """
 
     # check inputs
-    pitch = float(pitch)
+    pitch = np.asanyarray(pitch, dtype=np.float64)
     origin = np.asanyarray(origin, dtype=np.float64)
 
     # if resolution is None make it larger than path