diff --git a/doc/classes/MeshInstance3D.xml b/doc/classes/MeshInstance3D.xml
index abbb4c4eebd..d8e2c43566b 100644
--- a/doc/classes/MeshInstance3D.xml
+++ b/doc/classes/MeshInstance3D.xml
@@ -21,6 +21,14 @@
[b]Performance:[/b] [Mesh] data needs to be received from the GPU, stalling the [RenderingServer] in the process.
+
+
+
+
+ Takes a snapshot of the current animated skeleton pose of the skinned mesh and bakes it to the provided [param existing] mesh. If no [param existing] mesh is provided a new [ArrayMesh] is created, baked, and returned. Requires a skeleton with a registered skin to work. Blendshapes are ignored. Mesh surface materials are not copied.
+ [b]Performance:[/b] [Mesh] data needs to be retrieved from the GPU, stalling the [RenderingServer] in the process.
+
+
diff --git a/scene/3d/mesh_instance_3d.cpp b/scene/3d/mesh_instance_3d.cpp
index 987117a7a0d..f551cb401c5 100644
--- a/scene/3d/mesh_instance_3d.cpp
+++ b/scene/3d/mesh_instance_3d.cpp
@@ -671,6 +671,172 @@ Ref MeshInstance3D::bake_mesh_from_current_blend_shape_mix(Ref MeshInstance3D::bake_mesh_from_current_skeleton_pose(Ref p_existing) {
+ Ref source_mesh = get_mesh();
+ ERR_FAIL_COND_V_MSG(source_mesh.is_null(), Ref(), "The source mesh must be a valid ArrayMesh.");
+
+ Ref bake_mesh;
+
+ if (p_existing.is_valid()) {
+ ERR_FAIL_COND_V_MSG(source_mesh == p_existing, Ref(), "The source mesh can not be the same mesh as the existing mesh.");
+
+ bake_mesh = p_existing;
+ } else {
+ bake_mesh.instantiate();
+ }
+
+ ERR_FAIL_COND_V_MSG(skin_ref.is_null(), Ref(), "The source mesh must have a valid skin.");
+ ERR_FAIL_COND_V_MSG(skin_internal.is_null(), Ref(), "The source mesh must have a valid skin.");
+ RID skeleton = skin_ref->get_skeleton();
+ ERR_FAIL_COND_V_MSG(!skeleton.is_valid(), Ref(), "The source mesh must have its skin registered with a valid skeleton.");
+
+ const int bone_count = RenderingServer::get_singleton()->skeleton_get_bone_count(skeleton);
+ ERR_FAIL_COND_V(bone_count <= 0, Ref());
+ ERR_FAIL_COND_V(bone_count < skin_internal->get_bind_count(), Ref());
+
+ LocalVector bone_transforms;
+ bone_transforms.resize(bone_count);
+ for (int bone_index = 0; bone_index < bone_count; bone_index++) {
+ bone_transforms[bone_index] = RenderingServer::get_singleton()->skeleton_bone_get_transform(skeleton, bone_index);
+ }
+
+ bake_mesh->clear_surfaces();
+
+ int mesh_surface_count = source_mesh->get_surface_count();
+
+ for (int surface_index = 0; surface_index < mesh_surface_count; surface_index++) {
+ ERR_CONTINUE(source_mesh->surface_get_primitive_type(surface_index) != Mesh::PRIMITIVE_TRIANGLES);
+
+ uint32_t surface_format = source_mesh->surface_get_format(surface_index);
+
+ ERR_CONTINUE(0 == (surface_format & Mesh::ARRAY_FORMAT_VERTEX));
+ ERR_CONTINUE(0 == (surface_format & Mesh::ARRAY_FORMAT_BONES));
+ ERR_CONTINUE(0 == (surface_format & Mesh::ARRAY_FORMAT_WEIGHTS));
+
+ unsigned int bones_per_vertex = surface_format & Mesh::ARRAY_FLAG_USE_8_BONE_WEIGHTS ? 8 : 4;
+
+ surface_format &= ~Mesh::ARRAY_FORMAT_BONES;
+ surface_format &= ~Mesh::ARRAY_FORMAT_WEIGHTS;
+
+ const Array &source_mesh_arrays = source_mesh->surface_get_arrays(surface_index);
+
+ ERR_FAIL_COND_V(source_mesh_arrays.size() != RS::ARRAY_MAX, Ref());
+
+ const Vector &source_mesh_vertex_array = source_mesh_arrays[Mesh::ARRAY_VERTEX];
+ const Vector &source_mesh_normal_array = source_mesh_arrays[Mesh::ARRAY_NORMAL];
+ const Vector &source_mesh_tangent_array = source_mesh_arrays[Mesh::ARRAY_TANGENT];
+ const Vector &source_mesh_bones_array = source_mesh_arrays[Mesh::ARRAY_BONES];
+ const Vector &source_mesh_weights_array = source_mesh_arrays[Mesh::ARRAY_WEIGHTS];
+
+ unsigned int vertex_count = source_mesh_vertex_array.size();
+ int expected_bone_array_size = vertex_count * bones_per_vertex;
+ ERR_CONTINUE(source_mesh_bones_array.size() != expected_bone_array_size);
+ ERR_CONTINUE(source_mesh_weights_array.size() != expected_bone_array_size);
+
+ Array new_mesh_arrays;
+ new_mesh_arrays.resize(Mesh::ARRAY_MAX);
+ for (int i = 0; i < source_mesh_arrays.size(); i++) {
+ if (i == Mesh::ARRAY_VERTEX || i == Mesh::ARRAY_NORMAL || i == Mesh::ARRAY_TANGENT || i == Mesh::ARRAY_BONES || i == Mesh::ARRAY_WEIGHTS) {
+ continue;
+ }
+ new_mesh_arrays[i] = source_mesh_arrays[i];
+ }
+
+ bool use_normal_array = source_mesh_normal_array.size() == source_mesh_vertex_array.size();
+ bool use_tangent_array = source_mesh_tangent_array.size() / 4 == source_mesh_vertex_array.size();
+
+ Vector lerped_vertex_array = source_mesh_vertex_array;
+ Vector lerped_normal_array = source_mesh_normal_array;
+ Vector lerped_tangent_array = source_mesh_tangent_array;
+
+ const Vector3 *source_vertices_ptr = source_mesh_vertex_array.ptr();
+ const Vector3 *source_normals_ptr = source_mesh_normal_array.ptr();
+ const float *source_tangents_ptr = source_mesh_tangent_array.ptr();
+ const int *source_bones_ptr = source_mesh_bones_array.ptr();
+ const float *source_weights_ptr = source_mesh_weights_array.ptr();
+
+ Vector3 *lerped_vertices_ptrw = lerped_vertex_array.ptrw();
+ Vector3 *lerped_normals_ptrw = lerped_normal_array.ptrw();
+ float *lerped_tangents_ptrw = lerped_tangent_array.ptrw();
+
+ for (unsigned int vertex_index = 0; vertex_index < vertex_count; vertex_index++) {
+ Vector3 lerped_vertex;
+ Vector3 lerped_normal;
+ Vector3 lerped_tangent;
+
+ const Vector3 &source_vertex = source_vertices_ptr[vertex_index];
+
+ Vector3 source_normal;
+ if (use_normal_array) {
+ source_normal = source_normals_ptr[vertex_index];
+ }
+
+ int tangent_index = vertex_index * 4;
+ Vector4 source_tangent;
+ Vector3 source_tangent_vec3;
+ if (use_tangent_array) {
+ source_tangent = Vector4(
+ source_tangents_ptr[tangent_index],
+ source_tangents_ptr[tangent_index + 1],
+ source_tangents_ptr[tangent_index + 2],
+ source_tangents_ptr[tangent_index + 3]);
+
+ DEV_ASSERT(source_tangent.w == 1.0 || source_tangent.w == -1.0);
+
+ source_tangent_vec3 = Vector3(source_tangent.x, source_tangent.y, source_tangent.z);
+ }
+
+ for (unsigned int weight_index = 0; weight_index < bones_per_vertex; weight_index++) {
+ float bone_weight = source_weights_ptr[vertex_index * bones_per_vertex + weight_index];
+ if (bone_weight < FLT_EPSILON) {
+ continue;
+ }
+ int vertex_bone_index = source_bones_ptr[vertex_index * bones_per_vertex + weight_index];
+ const Transform3D &bone_transform = bone_transforms[vertex_bone_index];
+ const Basis bone_basis = bone_transform.basis.orthonormalized();
+
+ ERR_FAIL_INDEX_V(vertex_bone_index, static_cast(bone_transforms.size()), Ref());
+
+ lerped_vertex += source_vertex.lerp(bone_transform.xform(source_vertex), bone_weight) - source_vertex;
+ ;
+
+ if (use_normal_array) {
+ lerped_normal += source_normal.lerp(bone_basis.xform(source_normal), bone_weight) - source_normal;
+ }
+
+ if (use_tangent_array) {
+ lerped_tangent += source_tangent_vec3.lerp(bone_basis.xform(source_tangent_vec3), bone_weight) - source_tangent_vec3;
+ }
+ }
+
+ lerped_vertices_ptrw[vertex_index] += lerped_vertex;
+
+ if (use_normal_array) {
+ lerped_normals_ptrw[vertex_index] = (source_normal + lerped_normal).normalized();
+ }
+
+ if (use_tangent_array) {
+ lerped_tangent = (source_tangent_vec3 + lerped_tangent).normalized();
+ lerped_tangents_ptrw[tangent_index] = lerped_tangent.x;
+ lerped_tangents_ptrw[tangent_index + 1] = lerped_tangent.y;
+ lerped_tangents_ptrw[tangent_index + 2] = lerped_tangent.z;
+ }
+ }
+
+ new_mesh_arrays[Mesh::ARRAY_VERTEX] = lerped_vertex_array;
+ if (use_normal_array) {
+ new_mesh_arrays[Mesh::ARRAY_NORMAL] = lerped_normal_array;
+ }
+ if (use_tangent_array) {
+ new_mesh_arrays[Mesh::ARRAY_TANGENT] = lerped_tangent_array;
+ }
+
+ bake_mesh->add_surface_from_arrays(Mesh::PRIMITIVE_TRIANGLES, new_mesh_arrays, Array(), Dictionary(), surface_format);
+ }
+
+ return bake_mesh;
+}
+
void MeshInstance3D::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_mesh", "mesh"), &MeshInstance3D::set_mesh);
ClassDB::bind_method(D_METHOD("get_mesh"), &MeshInstance3D::get_mesh);
@@ -700,6 +866,7 @@ void MeshInstance3D::_bind_methods() {
ClassDB::bind_method(D_METHOD("create_debug_tangents"), &MeshInstance3D::create_debug_tangents);
ClassDB::bind_method(D_METHOD("bake_mesh_from_current_blend_shape_mix", "existing"), &MeshInstance3D::bake_mesh_from_current_blend_shape_mix, DEFVAL(Ref()));
+ ClassDB::bind_method(D_METHOD("bake_mesh_from_current_skeleton_pose", "existing"), &MeshInstance3D::bake_mesh_from_current_skeleton_pose, DEFVAL(Ref()));
ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "mesh", PROPERTY_HINT_RESOURCE_TYPE, "Mesh"), "set_mesh", "get_mesh");
ADD_GROUP("Skeleton", "");
diff --git a/scene/3d/mesh_instance_3d.h b/scene/3d/mesh_instance_3d.h
index 8a7e03c5b36..0eff12762dc 100644
--- a/scene/3d/mesh_instance_3d.h
+++ b/scene/3d/mesh_instance_3d.h
@@ -102,6 +102,7 @@ public:
virtual AABB get_aabb() const override;
Ref bake_mesh_from_current_blend_shape_mix(Ref p_existing = Ref());
+ Ref bake_mesh_from_current_skeleton_pose(Ref p_existing = Ref());
MeshInstance3D();
~MeshInstance3D();