collisionbox: add Minetest h symmetry, enable by default

utilities/blender/generate_lua_collisionbox.py

@@ -2,8 +2,19 @@ print("How to use: paste into a Blender Text Editor panel, select"
       " object, Run Script")
 
 y_up = True
-enable_minetest = False
+enable_minetest = True
-
+enable_lowest_h = False
+enable_center_h = False
+if enable_minetest:
+    enable_lowest_h = True
+    enable_center_h = True
+
+hs = (0, 1)  # horizontal axis indices
+v = 2  # vertical axis index
+# Do NOT swap until end.
+#if y_up:
+#    hs = (0, 2)
+#    v = 1
 
 import bpy
 # from mathutils import Matrix
@@ -54,7 +65,7 @@ if ob1 is not None:
 if ob1 is None:
     msg = "Nothing is selected."
     bpy.ops.message.messagebox('INVOKE_DEFAULT', message = msg)
-if (mesh is not None) and (not hasattr(mesh, 'vertices')):
+elif (mesh is not None) and (not hasattr(mesh, 'vertices')):
     msg = "Collision box for armatures cannot be calculated."
     bpy.ops.message.messagebox('INVOKE_DEFAULT', message = msg)
 else:
@@ -64,26 +75,14 @@ else:
     # See https://blender.stackexchange.com/questions/8459/get-blender-x-y-z-and-bounding-box-with-script
     # bbox_corners = [ob1.matrix_world * Vector(corner) for corner in ob1.bound_box]
 
-    # use ground as bottom (don't do this--it is not the Minetest way)
-    # if zMin < 0.0:
-    #     yMax -= yMin
-    #     yMin = 0.0
-
-    # print("    collisionbox = {{{:.2f}, {:.2f}, {:.2f}, {:.2f}, {:.2f},"
-          # " {:.2f}}}".format(xMin, yMin, zMin, xMax, yMax, zMax))
 
     # See https://blender.stackexchange.com/questions/6139/how-to-iterate-through-all-vertices-of-an-object-that-contains-multiple-meshes
     # print("mesh:" + str(mesh))
     # print("hasattr(mesh, 'vertices'):"
           # + str(hasattr(mesh, 'vertices')))]
-    xMin = None  # Define so None check is possible later.
+    mins = [None, None, None]  # minimums; in outer scope for checks.
+    maxes = [None, None, None]  # minimums; in outer scope for checks.
     if mesh is not None:
-        xMin = None
-        yMin = None
-        zMin = None
-        xMax = None
-        yMax = None
-        zMax = None
         wm = ob1.matrix_world
         for vert in mesh.vertices:
             # This matrix multiplication is NOT transitive.
@@ -91,24 +90,18 @@ else:
                 loc = wm @ vert.co
             except TypeError:
                 loc = wm * vert.co  # Blender <2.8
-            # switch y and z for Minetest (y-up)
+            # NOTE: swap y and z for Minetest (y-up) LATER
-            if (xMin is None) or (loc.x < xMin):
+            coords = (loc.x, loc.y, loc.z)
-                xMin = loc.x
+            for i in range(3):
-            if (xMax is None) or (loc.x > xMax):
+                if (mins[i] is None) or (coords[i] < mins[i]):
-                xMax = loc.x
+                    mins[i] = coords[i]
-            if (yMin is None) or (loc.y < yMin):
+                if (maxes[i] is None) or (coords[i] > maxes[i]):
-                yMin = loc.y
+                    maxes[i] = coords[i]
-            if (yMax is None) or (loc.y > yMax):
-                yMax = loc.y
-            if (zMin is None) or (loc.z < zMin):
-                zMin = loc.z
-            if (zMax is None) or (loc.z > zMax):
-                zMax = loc.z
         # print(str(extents1))
         # print("--by vertices (raw):")
-        print("    collisionbox = {{{:.2f}, {:.2f}, {:.2f}, {:.2f},"
+        # print("    collisionbox = {{{:.2f}, {:.2f}, {:.2f}, {:.2f},"
-              " {:.2f}, {:.2f}}}".format(xMin, yMin, zMin, xMax, yMax,
+              # " {:.2f}, {:.2f}}}".format(mins[0], mins[2], mins[1],
-                                         zMax))
+                                         # maxes[0], maxes[2], maxes[1]))
 
         # Use ob1.matrix_world (above) instead of incrementing
         # ob1.location.x, y, and z
@@ -124,14 +117,14 @@ else:
             # except TypeError:
                 # loc = wm * vert.co  # Blender <2.8
             # isFar = False
-            # if loc.x == xMax or loc.y == yMax or loc.z == zMax:
+            # if loc.x == maxes[0] or loc.y == maxes[1] or loc.z == maxes[2]:
                 # isFar = True
-            # elif loc.x == xMin or loc.y == yMin or loc.z == zMin:
+            # elif loc.x == mins[0] or loc.y == mins[1] or loc.z == mins[2]:
                 # isFar = True
             # if isFar:
                 # pass
                 # # result = bpy.ops.object.add(type='EMPTY', radius=.25,
-                                            # # location=loc);
+                                            # # location=loc)
                 # # NOTE: result is merely {'FINISHED'}
                 # # print("{:.2f}, {:.2f}, {:.2f}".format(loc.x, loc.y,
                                                       # # loc.z))
@@ -142,40 +135,83 @@ else:
     else:
         extents1 = ob1.scale.copy()
         # Object is an empty, so scale up for Minetest
-        extents1.x = extents1.x * 2.0
+        extents1.x = extents1.x * (ob1.empty_draw_size * 2.0)
-        extents1.y = extents1.y * 2.0
+        extents1.y = extents1.y * (ob1.empty_draw_size * 2.0)
-        extents1.z = extents1.z * 2.0
+        extents1.z = extents1.z * (ob1.empty_draw_size * 2.0)
-        xMin = obj1Loc.x - extents1.x / 2.0
+        mins[0] = obj1Loc.x - extents1.x / 2.0
-        xMax = obj1Loc.x + extents1.x / 2.0
+        maxes[0] = obj1Loc.x + extents1.x / 2.0
-        yMin = obj1Loc.y - extents1.y / 2.0
+        mins[1] = obj1Loc.y - extents1.y / 2.0
-        yMax = obj1Loc.y + extents1.y / 2.0
+        maxes[1] = obj1Loc.y + extents1.y / 2.0
-        zMin = obj1Loc.z - extents1.z / 2.0
+        mins[2] = obj1Loc.z - extents1.z / 2.0
-        zMax = obj1Loc.z + extents1.z / 2.0
+        maxes[2] = obj1Loc.z + extents1.z / 2.0
         msgSuffix = " (using Empty object's scale)"
         # print("--using empty object:")
-    # switch y and z for Minetest (y-up):
+
+    # use ground as bottom (don't do this--it is not the Minetest way)
+    # if mins[2] < 0.0:
+    #     maxes[1] -= mins[1]
+    #     mins[1] = 0.0
+
+    # print("    collisionbox = {{{:.2f}, {:.2f}, {:.2f}, {:.2f}, {:.2f},"
+          # " {:.2f}}}".format(mins[0], mins[1], mins[2], maxes[0], maxes[1], maxes[2]))
+    sizes = [None, None, None]
+    centers = [None, None, None]
+    for i in range(3):
+        sizes[i] = maxes[i] - mins[i]
+        centers[i] = mins[i] + sizes[i] / 2.0
+
+    if enable_lowest_h:
+        # OK to use z as up, since will y&z will be swapped if y_up
+        hSize = None
+        for i in range(len(hs)):
+            axis_i = hs[i]
+            if (hSize is None) or (sizes[axis_i] < hSize):
+                hSize = sizes[axis_i]
+        for i in range(len(hs)):
+            axis_i = hs[i]
+            sizes[axis_i] = hSize
+            mins[axis_i] = centers[axis_i] - hSize / 2
+            maxes[axis_i] = mins[axis_i] + hSize
+
+    if enable_center_h:
+        for i in range(len(hs)):
+            axis_i = hs[i]
+            centers[i] = 0
+            mins[axis_i] = centers[axis_i] - sizes[axis_i] / 2
+            maxes[axis_i] = mins[axis_i] + sizes[axis_i]
+
+    loc = (centers[0], centers[1], centers[2])
+    bpy.ops.object.add(type='EMPTY', radius=.5, location=loc)
+    collisionboxName = "Empty.collisionbox." + ob1.name
+    newEmpty = bpy.context.scene.objects.active
+    newEmpty.name = collisionboxName
+    newEmpty.location = (centers[0], centers[1], centers[2])
+    newEmpty.empty_draw_type = 'CUBE'
+    # newEmpty.empty_draw_size = (sizes[0], sizes[1], sizes[2])
+    # newEmpty.dimensions = (sizes[0], sizes[1], sizes[2])
+    # newEmpty.scale = (sizes[0]/2.0, sizes[1]/2.0, sizes[2]/2.0)
+    newEmpty.scale = (sizes[0], sizes[1], sizes[2])
+
     if enable_minetest:
-        xMin /= 10.0
+        for i in range(3):
-        xMax /= 10.0
+            mins[i] /= 10.0
-        yMin /= 10.0
+            maxes[i] /= 10.0
-        yMax /= 10.0
-        zMin /= 10.0
-        zMax /= 10.0
 
     msg = ('Size is not available. Make sure you have a mesh object'
            ' selected.')
 
-    if xMin is not None:
+    if mins[0] is not None:
+        # swap y and z for Minetest (y-up):
         if y_up:
-            tmp = yMin
+            tmp = mins[1]
-            yMin = zMin
+            mins[1] = mins[2]
-            zMin = tmp
+            mins[2] = tmp
-            tmp = yMax
+            tmp = maxes[1]
-            yMax = zMax
+            maxes[1] = maxes[2]
-            zMax = tmp
+            maxes[2] = tmp
         msg = ("    collisionbox = {{{:.2f}, {:.2f}, {:.2f}, {:.2f},"
-               " {:.2f}, {:.2f}}}".format(xMin, yMin, zMin, xMax, yMax,
+               " {:.2f}, {:.2f}}}".format(mins[0], mins[1], mins[2],
-                                          zMax))
+                                          maxes[0], maxes[1], maxes[2]))
         if len(msgSuffix) > 0:
             msgSuffix = "  -- " + msgSuffix
         bpy.context.window_manager.clipboard = msg + msgSuffix