functino to to create gridded version of existing slicing surface mesh

slicer/utils/surfaces.py

@@ -5,7 +5,7 @@ import sympy as sp
 from .general import copy_over_array, gen_single_surf
 
 
-def get_model_xy_grid(model_mesh, resolution):
+def get_model_xy_grid(model_mesh, resolution, bigger=True):
     """
     Get the xy grid used to generate the surfaces for slicing
     resolution: the number of points on the longer side
@@ -23,8 +23,12 @@ def get_model_xy_grid(model_mesh, resolution):
         res_x = int(resolution*x_len/y_len)
 
     # gen grid
-    x = np.linspace(min_x-1e-3, max_x+1e-3, res_x)
-    y = np.linspace(min_y-1e-3, max_y+1e-3, res_y)
+    if bigger:
+        x = np.linspace(min_x-1e-3, max_x+1e-3, res_x)
+        y = np.linspace(min_y-1e-3, max_y+1e-3, res_y)
+    else:
+        x = np.linspace(min_x, max_x, res_x)
+        y = np.linspace(min_y, max_y, res_y)
     x, y = np.meshgrid(x, y)
     return x, y
 
@@ -191,4 +195,22 @@ def gen_curved_surfs(model_mesh, resolution, roundness=0.003, z_max=1, z_start=1
         z = z_start + (z_top-z_start)*(z_m-z_start)/(z_top.max() - z_start)
         surfs.append(gen_single_surf(x, y, z))
         print("Surface {} of {} added".format(i,len(z_mids)))
-    return surfs
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+    return surfs
+
+
+def gen_grid_surf(surf_mesh, model_mesh, resolution):
+    """
+    Generate a structured grid from a surface mesh
+    """
+    surf_mesh = surf_mesh.extract_surface()
+    xall, yall = get_model_xy_grid(model_mesh, resolution, bigger=False)
+    zs = []
+
+    for x,y in zip(xall.flatten(), yall.flatten()):
+        ip, _ = surf_mesh.ray_trace((x,y,-1000), (x,y,1000), first_point=True)
+        if len(ip)==0:
+            ip = [x,y,surf_mesh.points.mean(axis=0)[2]]
+        zs.append(ip[2])
+
+    zall = np.array(zs).reshape(xall.shape)
+    return gen_single_surf(xall,yall,zall)
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