From 189c3af8b3cdeb3948ee3721dc6e5e0d6651674d Mon Sep 17 00:00:00 2001
From: smix8 <52464204+smix8@users.noreply.github.com>
Date: Wed, 26 Jun 2024 11:09:11 +0200
Subject: [PATCH] Add Mesh.create_convex_shapes() to expose convex
 decomposition for scripts

Adds Mesh.create_convex_shapes() functions so scripts can make use of the convex decomposition with MeshConvexDecompositionSettings parameters.
---
 doc/classes/Mesh.xml     |  7 +++++++
 scene/resources/mesh.cpp | 26 ++++++++++++++++++++++++++
 scene/resources/mesh.h   |  1 +
 3 files changed, 34 insertions(+)

diff --git a/doc/classes/Mesh.xml b/doc/classes/Mesh.xml
index 6b5a50d97b922..b299b4b6a650b 100644
--- a/doc/classes/Mesh.xml
+++ b/doc/classes/Mesh.xml
@@ -120,6 +120,13 @@
 				If [param simplify] is [code]true[/code], the geometry can be further simplified to reduce the number of vertices. Disabled by default.
 			</description>
 		</method>
+		<method name="create_convex_shapes" qualifiers="const">
+			<return type="Array" />
+			<param index="0" name="settings" type="MeshConvexDecompositionSettings" default="null" />
+			<description>
+				Creates one or more [ConvexPolygonShape3D] collision shapes calculated from the mesh geometry via convex decomposition. The convex decomposition operation can be controlled with parameters from the optional [param settings].
+			</description>
+		</method>
 		<method name="create_outline" qualifiers="const">
 			<return type="Mesh" />
 			<param index="0" name="margin" type="float" />
diff --git a/scene/resources/mesh.cpp b/scene/resources/mesh.cpp
index 8b5e438aea62a..d1e037142df56 100644
--- a/scene/resources/mesh.cpp
+++ b/scene/resources/mesh.cpp
@@ -811,6 +811,10 @@ void Mesh::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("surface_set_material", "surf_idx", "material"), &Mesh::surface_set_material);
 	ClassDB::bind_method(D_METHOD("surface_get_material", "surf_idx"), &Mesh::surface_get_material);
 	ClassDB::bind_method(D_METHOD("create_placeholder"), &Mesh::create_placeholder);
+#ifndef _3D_DISABLED
+	ClassDB::bind_method(D_METHOD("create_convex_shapes", "settings"), &Mesh::create_convex_shapes, DEFVAL(Ref<MeshConvexDecompositionSettings>()));
+	ClassDB::set_method_flags("Mesh", "create_convex_shapes", METHOD_FLAGS_DEFAULT);
+#endif // _3D_DISABLED
 
 	BIND_ENUM_CONSTANT(PRIMITIVE_POINTS);
 	BIND_ENUM_CONSTANT(PRIMITIVE_LINES);
@@ -901,6 +905,28 @@ void Mesh::clear_cache() const {
 }
 
 #ifndef _3D_DISABLED
+Array Mesh::create_convex_shapes(const Ref<MeshConvexDecompositionSettings> &p_settings) const {
+	Ref<MeshConvexDecompositionSettings> settings;
+	if (p_settings.is_valid()) {
+		settings = p_settings;
+	} else {
+		settings.instantiate();
+		settings->set_max_convex_hulls(32);
+		settings->set_max_concavity(0.001);
+	}
+
+	Vector<Ref<Shape3D>> decomposed_shapes = convex_decompose(settings);
+
+	Array ret;
+	ret.resize(decomposed_shapes.size());
+
+	for (int i = 0; i < decomposed_shapes.size(); i++) {
+		ret[i] = static_cast<Ref<ConvexPolygonShape3D>>(decomposed_shapes[i]);
+	}
+
+	return ret;
+}
+
 Vector<Ref<Shape3D>> Mesh::convex_decompose(const Ref<MeshConvexDecompositionSettings> &p_settings) const {
 	ERR_FAIL_NULL_V(convex_decomposition_function, Vector<Ref<Shape3D>>());
 
diff --git a/scene/resources/mesh.h b/scene/resources/mesh.h
index 13fd986e811d5..9a6c2f06a70f8 100644
--- a/scene/resources/mesh.h
+++ b/scene/resources/mesh.h
@@ -199,6 +199,7 @@ class Mesh : public Resource {
 #ifndef _3D_DISABLED
 	Vector<Ref<Shape3D>> convex_decompose(const Ref<MeshConvexDecompositionSettings> &p_settings) const;
 	Ref<ConvexPolygonShape3D> create_convex_shape(bool p_clean = true, bool p_simplify = false) const;
+	Array create_convex_shapes(const Ref<MeshConvexDecompositionSettings> &p_settings) const;
 	Ref<ConcavePolygonShape3D> create_trimesh_shape() const;
 #endif // _3D_DISABLED