Derive AABB mins/maxs from brush vertex data

Author: MotoLegacy

spawn_zone_tool.py

@@ -5,10 +5,13 @@
 from typing import Dict, List, Tuple, Optional
 
 import sys
+import math
+import itertools
 
 SCRIPT_DIR = Path(__file__).resolve().parent
 sys.path.insert(0, str(SCRIPT_DIR))
 
+from panda3d.core import Vec3
 from p3d_libmap.map_parser import MapParser
 
 
@@ -43,23 +46,126 @@ def load_map_without_geo(path: Path):
     return parser.map_data
 
 
-def get_bounds_for_brush(brush, origin=(0.0, 0.0, 0.0)):
-    """Compute min/max bounds for a brush."""
-    ox, oy, oz = origin
+def _vec_sub(a, b):
+    return (a[0] - b[0], a[1] - b[1], a[2] - b[2])
 
-    xs, ys, zs = [], [], []
+def _vec_add(a, b):
+    return (a[0] + b[0], a[1] + b[1], a[2] + b[2])
 
-    for face in brush.faces:
-        pts = (face.plane_points.v0, face.plane_points.v1, face.plane_points.v2)
-        for p in pts:
-            xs.append(p.x + ox)
-            ys.append(p.y + oy)
-            zs.append(p.z + oz)
+def _vec_dot(a, b):
+    return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]
+
+def _vec_cross(a, b):
+    return (
+        a[1]*b[2] - a[2]*b[1],
+        a[2]*b[0] - a[0]*b[2],
+        a[0]*b[1] - a[1]*b[0],
+    )
 
-    if not xs:
+def _vec_scale(v, s):
+    return (v[0]*s, v[1]*s, v[2]*s)
+
+def _vec_len(v):
+    return math.sqrt(_vec_dot(v, v))
+
+def _vec_norm(v):
+    l = _vec_len(v)
+    if l == 0.0:
+        return (0.0, 0.0, 0.0)
+    return (v[0]/l, v[1]/l, v[2]/l)
+
+def _plane_from_face(face):
+    # p1, p2, p3 are any 3 points on the plane
+    p1 = (face.plane_points.v0.x, face.plane_points.v0.y, face.plane_points.v0.z)
+    p2 = (face.plane_points.v1.x, face.plane_points.v1.y, face.plane_points.v1.z)
+    p3 = (face.plane_points.v2.x, face.plane_points.v2.y, face.plane_points.v2.z)
+
+    # normal = normalize((p3 - p1) x (p2 - p1))  (matches your format description)
+    n = _vec_cross(_vec_sub(p3, p1), _vec_sub(p2, p1))
+    n = _vec_norm(n)
+
+    # Plane equation: n·x = d
+    d = _vec_dot(n, p1)
+
+    # Half-space rule from your docs:
+    # points p where (p - p1)·n <= 0 are inside
+    # => n·p <= n·p1 == d is inside
+    return n, d
+
+def _intersect_3_planes(p1, p2, p3, eps=1e-9):
+    # Planes: n·x = d
+    (n1, d1) = p1
+    (n2, d2) = p2
+    (n3, d3) = p3
+
+    n2xn3 = _vec_cross(n2, n3)
+    denom = _vec_dot(n1, n2xn3)
+
+    if abs(denom) < eps:
+        return None  # parallel / no single point intersection
+
+    term1 = _vec_scale(n2xn3, d1)
+    term2 = _vec_scale(_vec_cross(n3, n1), d2)
+    term3 = _vec_scale(_vec_cross(n1, n2), d3)
+
+    x = _vec_scale(_vec_add(_vec_add(term1, term2), term3), 1.0 / denom)
+    return x
+
+def get_vertices_for_brush(brush, epsilon=0.05):
+    """
+    Return a list of world-space vertices for a convex Quake brush by intersecting planes.
+    epsilon is in Quake units.
+    """
+    planes = []
+    for face in brush.faces:
+        n, d = _plane_from_face(face)
+        # Skip degenerate faces
+        if _vec_len(n) == 0.0:
+            continue
+        planes.append((n, d))
+
+    verts = []
+    for i in range(len(planes)):
+        for j in range(i + 1, len(planes)):
+            for k in range(j + 1, len(planes)):
+                p = _intersect_3_planes(planes[i], planes[j], planes[k])
+                if p is None:
+                    continue
+
+                # Inside test: n·p <= d + epsilon for all planes
+                inside = True
+                for (n, d) in planes:
+                    if _vec_dot(n, p) > d + epsilon:
+                        inside = False
+                        break
+                if not inside:
+                    continue
+
+                # Dedupe near-identical points
+                dup = False
+                for q in verts:
+                    if (abs(p[0] - q[0]) <= epsilon and
+                        abs(p[1] - q[1]) <= epsilon and
+                        abs(p[2] - q[2]) <= epsilon):
+                        dup = True
+                        break
+                if not dup:
+                    verts.append(p)
+
+    return verts
+
+def get_aabb_for_brush(brush, epsilon=0.05):
+    verts = get_vertices_for_brush(brush, epsilon=epsilon)
+    if not verts:
         return None, None
 
-    return (min(xs), min(ys), min(zs)), (max(xs), max(ys), max(zs))
+    xs = [v[0] for v in verts]
+    ys = [v[1] for v in verts]
+    zs = [v[2] for v in verts]
+
+    mins = (min(xs), min(ys), min(zs))
+    maxs = (max(xs), max(ys), max(zs))
+    return mins, maxs
 
 
 # ---------------------------------------------------------------------------
@@ -132,7 +238,11 @@ def get_id_for_zone(name: str) -> int:
         # Zone brushes
         brushes = []
         for i, brush in enumerate(ent.brushes):
-            mins, maxs = get_bounds_for_brush(brush)
+            mins, maxs = get_aabb_for_brush(brush)
+            if mins is None or maxs is None:
+                print(f"   * Brush {i}: (no points?)")
+                continue
+
             brushes.append(ZoneBrush(mins=mins, maxs=maxs))
             print(f"   * Brush {i}: mins={mins}, maxs={maxs}")
 
@@ -184,4 +294,4 @@ def main():
 
 
 if __name__ == "__main__":
-    main()
+    main()

tests/nszs/nzp_warehouse2.nsz

@@ -8,7 +8,7 @@ z1
 1
 1
 -1104.0 -852.0 304.0
--3.0 -348.0 440.0
+-4.0 -348.0 440.0
 spawn_zone_up
 1
 z9
@@ -17,7 +17,7 @@ z9
 2
 1
 -1108.0 -852.0 440.0
--3.0 -348.0 576.0
+-4.0 -348.0 576.0
 trench_zone
 4
 z5
@@ -26,7 +26,7 @@ z5
 3
 1
 -2220.0 -852.0 304.0
--1119.0 -348.0 440.0
+-1120.0 -348.0 440.0
 trench_zone_up
 3
 z11
@@ -35,7 +35,7 @@ z11
 4
 1
 -2220.0 -852.0 440.0
--1115.0 -348.0 576.0
+-1116.0 -348.0 576.0
 outdoor_zone
 6
 z6
@@ -45,7 +45,7 @@ z6
 5
 1
 -2224.0 -332.0 304.0
--1123.0 172.0 440.0
+-1124.0 172.0 440.0
 mule_zone
 5
 z7
@@ -55,7 +55,7 @@ z7
 6
 1
 -1104.0 -324.0 304.0
--3.0 180.0 576.0
+-4.0 180.0 576.0
 big_zone_left
 9
 z8

tests/nszs/nzp_zone_test.nsz

@@ -9,12 +9,12 @@ activate_zombs_1
 2
 3
 3
-44.0 -96.0 0.0
-97.0 65.0 144.0
--64.0 -96.0 0.0
--11.0 65.0 144.0
--12.0 -96.0 0.0
-44.0 65.0 144.0
+44.0 -96.0 -0.0
+96.0 64.0 144.0
+-64.0 -96.0 -0.0
+-12.0 64.0 144.0
+-12.0 -96.0 -0.0
+44.0 64.0 144.0
 number_2
 3
 activate_zombs_2
@@ -26,12 +26,12 @@ activate_zombs_2
 5
 6
 3
-204.0 -96.0 0.0
-257.0 65.0 144.0
-96.0 -96.0 0.0
-149.0 65.0 144.0
-148.0 -96.0 0.0
-204.0 65.0 144.0
+204.0 -96.0 -0.0
+256.0 64.0 144.0
+96.0 -96.0 -0.0
+148.0 64.0 144.0
+148.0 -96.0 -0.0
+204.0 64.0 144.0
 number_3
 6
 activate_zombs_3
@@ -41,12 +41,12 @@ activate_zombs_3
 2
 5
 3
-364.0 -96.0 0.0
-417.0 65.0 144.0
-256.0 -96.0 0.0
-309.0 65.0 144.0
-308.0 -96.0 0.0
-364.0 65.0 144.0
+364.0 -96.0 -0.0
+416.0 64.0 144.0
+256.0 -96.0 -0.0
+308.0 64.0 144.0
+308.0 -96.0 -0.0
+364.0 64.0 144.0
 number_4
 1
 activate_zombs_4
@@ -58,12 +58,12 @@ activate_zombs_4
 7
 8
 3
-44.0 -256.0 0.0
-97.0 -95.0 144.0
--64.0 -256.0 0.0
--11.0 -95.0 144.0
--12.0 -256.0 0.0
-44.0 -95.0 144.0
+44.0 -256.0 -0.0
+96.0 -96.0 144.0
+-64.0 -256.0 -0.0
+-12.0 -96.0 144.0
+-12.0 -256.0 -0.0
+44.0 -96.0 144.0
 number_5
 2
 activate_zombs_5
@@ -78,12 +78,12 @@ activate_zombs_5
 8
 9
 3
-204.0 -256.0 0.0
-257.0 -95.0 144.0
-96.0 -256.0 0.0
-149.0 -95.0 144.0
-148.0 -256.0 0.0
-204.0 -95.0 144.0
+204.0 -256.0 -0.0
+256.0 -96.0 144.0
+96.0 -256.0 -0.0
+148.0 -96.0 144.0
+148.0 -256.0 -0.0
+204.0 -96.0 144.0
 number_6
 5
 activate_zombs_6
@@ -95,12 +95,12 @@ activate_zombs_6
 8
 9
 3
-364.0 -256.0 0.0
-417.0 -95.0 144.0
-256.0 -256.0 0.0
-309.0 -95.0 144.0
-308.0 -256.0 0.0
-364.0 -95.0 144.0
+364.0 -256.0 -0.0
+416.0 -96.0 144.0
+256.0 -256.0 -0.0
+308.0 -96.0 144.0
+308.0 -256.0 -0.0
+364.0 -96.0 144.0
 number_7
 7
 activate_zombs_7
@@ -110,12 +110,12 @@ activate_zombs_7
 2
 8
 3
-44.0 -416.0 0.0
-97.0 -255.0 144.0
--64.0 -416.0 0.0
--11.0 -255.0 144.0
--12.0 -416.0 0.0
-44.0 -255.0 144.0
+44.0 -416.0 -0.0
+96.0 -256.0 144.0
+-64.0 -416.0 -0.0
+-12.0 -256.0 144.0
+-12.0 -416.0 -0.0
+44.0 -256.0 144.0
 number_8
 8
 activate_zombs_8
@@ -127,12 +127,12 @@ activate_zombs_8
 7
 9
 3
-204.0 -416.0 0.0
-257.0 -255.0 144.0
-96.0 -416.0 0.0
-149.0 -255.0 144.0
-148.0 -416.0 0.0
-204.0 -255.0 144.0
+204.0 -416.0 -0.0
+256.0 -256.0 144.0
+96.0 -416.0 -0.0
+148.0 -256.0 144.0
+148.0 -416.0 -0.0
+204.0 -256.0 144.0
 number_9
 9
 activate_zombs_9
@@ -142,9 +142,9 @@ activate_zombs_9
 5
 8
 3
-364.0 -416.0 0.0
-417.0 -255.0 144.0
-256.0 -416.0 0.0
-309.0 -255.0 144.0
-308.0 -416.0 0.0
-364.0 -255.0 144.0
+364.0 -416.0 -0.0
+416.0 -256.0 144.0
+256.0 -416.0 -0.0
+308.0 -256.0 144.0
+308.0 -416.0 -0.0
+364.0 -256.0 144.0