mesh_outline_projection #1

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theoryshaw merged 6 commits from mesh_outline_projection into main 2026-02-08 20:55:25 +00:00
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@ -14,6 +14,61 @@ from mathutils import Vector
from mathutils.bvhtree import BVHTree from mathutils.bvhtree import BVHTree
def point_in_polygon_2d(point, polygon_verts):
"""Check if a 2D point is inside a 2D polygon using ray casting algorithm"""
x, y = point[0], point[1]
n = len(polygon_verts)
inside = False
p1x, p1y = polygon_verts[0]
for i in range(1, n + 1):
p2x, p2y = polygon_verts[i % n]
if y > min(p1y, p2y):
if y <= max(p1y, p2y):
if x <= max(p1x, p2x):
if p1y != p2y:
xinters = (y - p1y) * (p2x - p1x) / (p2y - p1y) + p1x
if p1x == p2x or x <= xinters:
inside = not inside
p1x, p1y = p2x, p2y
return inside
def point_near_polygon_edge(point, polygon_verts, tolerance=0.05):
"""Check if a point is very close to any polygon edge"""
x, y = point[0], point[1]
n = len(polygon_verts)
for i in range(n):
p1x, p1y = polygon_verts[i]
p2x, p2y = polygon_verts[(i + 1) % n]
# Calculate distance from point to line segment
# Vector from p1 to p2
dx = p2x - p1x
dy = p2y - p1y
if dx == 0 and dy == 0:
# Degenerate edge
dist = ((x - p1x)**2 + (y - p1y)**2)**0.5
else:
# Parameter t for closest point on line segment
t = max(0, min(1, ((x - p1x) * dx + (y - p1y) * dy) / (dx * dx + dy * dy)))
# Closest point on line segment
closest_x = p1x + t * dx
closest_y = p1y + t * dy
# Distance to closest point
dist = ((x - closest_x)**2 + (y - closest_y)**2)**0.5
if dist < tolerance:
return True
return False
def get_object_outline_edges_2d(obj, context): def get_object_outline_edges_2d(obj, context):
"""Get the outline edges of an object when viewed from above (Z-axis)""" """Get the outline edges of an object when viewed from above (Z-axis)"""
print(f"\n=== Getting outline edges for: {obj.name} ===") print(f"\n=== Getting outline edges for: {obj.name} ===")
@ -232,94 +287,157 @@ def project_outline_to_mesh(context, source_obj, target_obj, outline_edges):
bm.faces.ensure_lookup_table() bm.faces.ensure_lookup_table()
bm.edges.ensure_lookup_table() bm.edges.ensure_lookup_table()
print(f" Creating vertical cutting planes from outline edges...") print(f" Creating outline curve for knife projection...")
# Get transformation matrix to convert from world to target local space # Get transformation matrix to convert from world to target local space
target_matrix_inv = target_obj.matrix_world.inverted() target_matrix_inv = target_obj.matrix_world.inverted()
# Identify horizontal edges (those in the XY plane that form the perimeter) # Get horizontal perimeter edges
# These are edges where both vertices have similar Z values
horizontal_edges = [] horizontal_edges = []
for v1, v2 in outline_edges: for v1, v2 in outline_edges:
z_diff = abs(v1.z - v2.z) z_diff = abs(v1.z - v2.z)
xy_dist = ((v1.x - v2.x)**2 + (v1.y - v2.y)**2)**0.5 xy_dist = ((v1.x - v2.x)**2 + (v1.y - v2.y)**2)**0.5
# If edge is mostly horizontal (small Z difference, significant XY distance)
if z_diff < 0.01 and xy_dist > 0.01: if z_diff < 0.01 and xy_dist > 0.01:
horizontal_edges.append((v1, v2)) horizontal_edges.append((v1, v2))
print(f" Found {len(horizontal_edges)} horizontal perimeter edges") print(f" Found {len(horizontal_edges)} horizontal perimeter edges (before deduplication)")
# For each horizontal edge, create a vertical cutting plane # Deduplicate edges
cuts_performed = 0 unique_edges_normalized = []
for i, (v1_world, v2_world) in enumerate(horizontal_edges): tolerance = 0.01
# Transform edge vertices to target's local space
v1_local = target_matrix_inv @ v1_world
v2_local = target_matrix_inv @ v2_world
# Edge vector in XY (local space) for v1, v2 in horizontal_edges:
edge_vec = Vector((v2_local.x - v1_local.x, v2_local.y - v1_local.y, 0)) if v1.x < v2.x or (abs(v1.x - v2.x) < tolerance and v1.y < v2.y):
edge_vec.normalize() edge_normalized = (v1, v2)
else:
edge_normalized = (v2, v1)
# Plane normal perpendicular to edge (in XY, pointing inward/outward) is_duplicate = False
plane_normal = Vector((-edge_vec.y, edge_vec.x, 0)) for existing_v1, existing_v2 in unique_edges_normalized:
plane_normal.normalize() if (abs(edge_normalized[0].x - existing_v1.x) < tolerance and
abs(edge_normalized[0].y - existing_v1.y) < tolerance and
abs(edge_normalized[1].x - existing_v2.x) < tolerance and
abs(edge_normalized[1].y - existing_v2.y) < tolerance):
is_duplicate = True
break
# Plane point (use v1 in local space) if not is_duplicate:
plane_co = v1_local.copy() unique_edges_normalized.append(edge_normalized)
if i < 3: print(f" Deduplicated to {len(unique_edges_normalized)} unique edges")
print(f" Cut {i}: plane at ({plane_co.x:.2f}, {plane_co.y:.2f}) [local], normal ({plane_normal.x:.2f}, {plane_normal.y:.2f})")
# Perform bisect # Build ordered polygon from edges for point-in-polygon testing
geom = bm.verts[:] + bm.edges[:] + bm.faces[:] # Start with first edge
result = bmesh.ops.bisect_plane( polygon_verts_2d = [unique_edges_normalized[0][0], unique_edges_normalized[0][1]]
bm, used_edges = {0}
geom=geom,
dist=0.001,
plane_co=plane_co,
plane_no=plane_normal,
clear_outer=False,
clear_inner=False
)
cuts_performed += 1
print(f" Performed {cuts_performed} cutting plane operations") # Connect edges to form a closed loop
for _ in range(len(unique_edges_normalized) - 1):
last_point = polygon_verts_2d[-1]
bmesh.update_edit_mesh(target_obj.data) # Find next connected edge
for i, (v1, v2) in enumerate(unique_edges_normalized):
if i in used_edges:
continue
# Refresh bmesh references after cuts # Check if this edge connects to our last point
v1_2d = (v1.x, v1.y)
v2_2d = (v2.x, v2.y)
last_2d = (last_point.x, last_point.y)
tolerance = 0.01
if abs(v1_2d[0] - last_2d[0]) < tolerance and abs(v1_2d[1] - last_2d[1]) < tolerance:
polygon_verts_2d.append(v2)
used_edges.add(i)
break
elif abs(v2_2d[0] - last_2d[0]) < tolerance and abs(v2_2d[1] - last_2d[1]) < tolerance:
polygon_verts_2d.append(v1)
used_edges.add(i)
break
# Remove duplicate endpoint if polygon is closed
if len(polygon_verts_2d) > 0:
first = polygon_verts_2d[0]
last = polygon_verts_2d[-1]
if abs(first.x - last.x) < 0.01 and abs(first.y - last.y) < 0.01:
polygon_verts_2d = polygon_verts_2d[:-1]
# Convert to 2D coordinates in world space for polygon testing
polygon_2d_world = [(v.x, v.y) for v in polygon_verts_2d]
print(f" Built polygon with {len(polygon_2d_world)} vertices for point-in-polygon testing")
print(f" Polygon vertices (world space):")
for i, (x, y) in enumerate(polygon_2d_world):
print(f" Vertex {i}: ({x:.2f}, {y:.2f})")
# Create curve object from unique edges
curve_data = bpy.data.curves.new(name=f"{source_obj.name}_outline", type='CURVE')
curve_data.dimensions = '3D'
for v1, v2 in unique_edges_normalized:
spline = curve_data.splines.new('POLY')
spline.points.add(1)
spline.points[0].co = (v1.x, v1.y, v1.z, 1)
spline.points[1].co = (v2.x, v2.y, v2.z, 1)
curve_obj = bpy.data.objects.new(f"{source_obj.name}_outline", curve_data)
context.collection.objects.link(curve_obj)
print(f" Created curve with {len(unique_edges_normalized)} splines")
# Set view to top orthographic
original_view_data = None
for area in context.screen.areas:
if area.type == 'VIEW_3D':
for space in area.spaces:
if space.type == 'VIEW_3D':
from mathutils import Quaternion
original_view_data = {
'rotation': space.region_3d.view_rotation.copy(),
'perspective': space.region_3d.view_perspective,
'distance': space.region_3d.view_distance
}
space.region_3d.view_rotation = Quaternion((1.0, 0.0, 0.0, 0.0))
space.region_3d.view_perspective = 'ORTHO'
break
# Switch back to object mode to select objects
bpy.ops.object.mode_set(mode='OBJECT')
# Deselect all
bpy.ops.object.select_all(action='DESELECT')
# Select curve and target
curve_obj.select_set(True)
target_obj.select_set(True)
context.view_layer.objects.active = target_obj
# Switch to edit mode for knife_project
bpy.ops.object.mode_set(mode='EDIT')
bpy.ops.mesh.select_all(action='DESELECT')
# Use knife project
print(f" Running knife_project...")
bpy.ops.mesh.knife_project(cut_through=False)
# Restore view
if original_view_data:
for area in context.screen.areas:
if area.type == 'VIEW_3D':
for space in area.spaces:
if space.type == 'VIEW_3D':
space.region_3d.view_rotation = original_view_data['rotation']
space.region_3d.view_perspective = original_view_data['perspective']
space.region_3d.view_distance = original_view_data['distance']
break
# Get bmesh for material assignment
bm = bmesh.from_edit_mesh(target_obj.data) bm = bmesh.from_edit_mesh(target_obj.data)
bm.faces.ensure_lookup_table() bm.faces.ensure_lookup_table()
print(f" Mesh cutting complete, now assigning materials...") print(f" Mesh cutting complete, now assigning materials...")
# Calculate 2D bounding box of the outline (in world space)
min_x_world = min(min(v1.x, v2.x) for v1, v2 in outline_edges)
max_x_world = max(max(v1.x, v2.x) for v1, v2 in outline_edges)
min_y_world = min(min(v1.y, v2.y) for v1, v2 in outline_edges)
max_y_world = max(max(v1.y, v2.y) for v1, v2 in outline_edges)
print(f" Outline 2D bounds (world space): X=[{min_x_world:.2f}, {max_x_world:.2f}], Y=[{min_y_world:.2f}, {max_y_world:.2f}]")
# Transform bounds to target object's local space (reuse matrix from cutting)
# Transform the 4 corners of the bounding box
corner_min_min = target_matrix_inv @ Vector((min_x_world, min_y_world, 0))
corner_min_max = target_matrix_inv @ Vector((min_x_world, max_y_world, 0))
corner_max_min = target_matrix_inv @ Vector((max_x_world, min_y_world, 0))
corner_max_max = target_matrix_inv @ Vector((max_x_world, max_y_world, 0))
# Get new bounds in local space
all_x = [corner_min_min.x, corner_min_max.x, corner_max_min.x, corner_max_max.x]
all_y = [corner_min_min.y, corner_min_max.y, corner_max_min.y, corner_max_max.y]
min_x_local = min(all_x)
max_x_local = max(all_x)
min_y_local = min(all_y)
max_y_local = max(all_y)
print(f" Outline 2D bounds (target local space): X=[{min_x_local:.2f}, {max_x_local:.2f}], Y=[{min_y_local:.2f}, {max_y_local:.2f}]")
# Assign material to faces within bounds # Assign material to faces within bounds
if material_index >= 0: if material_index >= 0:
source_min_z_world = min(min(v1.z, v2.z) for v1, v2 in outline_edges) source_min_z_world = min(min(v1.z, v2.z) for v1, v2 in outline_edges)
@ -327,24 +445,60 @@ def project_outline_to_mesh(context, source_obj, target_obj, outline_edges):
source_max_z_local = (target_matrix_inv @ Vector((0, 0, source_max_z_world))).z source_max_z_local = (target_matrix_inv @ Vector((0, 0, source_max_z_world))).z
print(f" Source Z max: {source_max_z_world:.2f} (world), {source_max_z_local:.2f} (target local)") print(f" Source Z max: {source_max_z_world:.2f} (world), {source_max_z_local:.2f} (target local)")
print(f" Material assignment: ALL vertices inside or on edge (tolerance: 0.05)")
faces_assigned = 0 faces_assigned = 0
faces_rejected_outside_polygon = 0
faces_rejected_z = 0
for face in bm.faces: for face in bm.faces:
face_center = face.calc_center_median() face_center = face.calc_center_median()
# Face center is already in target's local space (we're in edit mode) # First check Z (quick rejection)
# Check if within XY bounds and below source below_z = face_center.z < source_max_z_local
if (min_x_local <= face_center.x <= max_x_local and if not below_z:
min_y_local <= face_center.y <= max_y_local and faces_rejected_z += 1
face_center.z < source_max_z_local): continue
# Check if ALL vertices are inside or on/near the polygon boundary
all_verts_inside = True
verts_checked = 0
for vert in face.verts:
vert_world = target_obj.matrix_world @ vert.co
# Check Z first
if vert_world.z >= source_max_z_world:
all_verts_inside = False
break
# Check if vertex is inside polygon OR on/near the edge (with tolerance)
inside = point_in_polygon_2d((vert_world.x, vert_world.y), polygon_2d_world)
on_edge = point_near_polygon_edge((vert_world.x, vert_world.y), polygon_2d_world, tolerance=0.05)
if not (inside or on_edge):
all_verts_inside = False
break
verts_checked += 1
if all_verts_inside and verts_checked > 0:
face.material_index = material_index face.material_index = material_index
faces_assigned += 1 faces_assigned += 1
if faces_assigned <= 3: if faces_assigned <= 5:
print(f" Assigned material to face at ({face_center.x:.2f}, {face_center.y:.2f}, {face_center.z:.2f}) [local]") face_center_world = target_obj.matrix_world @ face_center
print(f" ✓ Face {faces_assigned}: ({face_center.x:.2f}, {face_center.y:.2f}, {face_center.z:.2f}) [local] -> ({face_center_world.x:.2f}, {face_center_world.y:.2f}) [world]")
else:
faces_rejected_outside_polygon += 1
if faces_rejected_outside_polygon <= 5:
face_center_world = target_obj.matrix_world @ face_center
print(f" ✗ Outside polygon: ({face_center.x:.2f}, {face_center.y:.2f}, {face_center.z:.2f}) [local] -> ({face_center_world.x:.2f}, {face_center_world.y:.2f}) [world]")
print(f" Assigned material to {faces_assigned} faces") print(f" Material assignment results:")
print(f" Assigned: {faces_assigned}")
print(f" Rejected - Outside polygon: {faces_rejected_outside_polygon}")
print(f" Rejected - Z too high: {faces_rejected_z}")
bmesh.update_edit_mesh(target_obj.data) bmesh.update_edit_mesh(target_obj.data)
@ -352,6 +506,11 @@ def project_outline_to_mesh(context, source_obj, target_obj, outline_edges):
bpy.ops.object.mode_set(mode='OBJECT') bpy.ops.object.mode_set(mode='OBJECT')
print(f" Returned to OBJECT mode") print(f" Returned to OBJECT mode")
# Clean up temporary curve object
bpy.data.objects.remove(curve_obj, do_unlink=True)
bpy.data.curves.remove(curve_data)
print(f" Cleaned up temporary curve")
# Verify material assignment # Verify material assignment
if material_index >= 0: if material_index >= 0:
print(f"\n Post-assignment verification:") print(f"\n Post-assignment verification:")