3 files changed, 83 insertions, 11 deletions

diff --git a/scene/3d/sprite_3d.cpp b/scene/3d/sprite_3d.cpp
index d833e6a8bb..036a748c83 100644
--- a/scene/3d/sprite_3d.cpp
+++ b/scene/3d/sprite_3d.cpp
@@ -185,6 +185,9 @@ void SpriteBase3D::_queue_update() {
 	if (pending_update)
 		return;
 
+	triangle_mesh.unref();
+	update_gizmo();
+
 	pending_update = true;
 	call_deferred(SceneStringNames::get_singleton()->_im_update);
 }
@@ -198,6 +201,66 @@ PoolVector<Face3> SpriteBase3D::get_faces(uint32_t p_usage_flags) const {
 	return PoolVector<Face3>();
 }
 
+Ref<TriangleMesh> SpriteBase3D::generate_triangle_mesh() const {
+	if (triangle_mesh.is_valid())
+		return triangle_mesh;
+
+	PoolVector<Vector3> faces;
+	faces.resize(6);
+	PoolVector<Vector3>::Write facesw = faces.write();
+
+	Rect2 final_rect = get_item_rect();
+
+	if (final_rect.size.x == 0 || final_rect.size.y == 0)
+		return Ref<TriangleMesh>();
+
+	float pixel_size = get_pixel_size();
+
+	Vector2 vertices[4] = {
+
+		(final_rect.position + Vector2(0, final_rect.size.y)) * pixel_size,
+		(final_rect.position + final_rect.size) * pixel_size,
+		(final_rect.position + Vector2(final_rect.size.x, 0)) * pixel_size,
+		final_rect.position * pixel_size,
+
+	};
+
+	int x_axis = ((axis + 1) % 3);
+	int y_axis = ((axis + 2) % 3);
+
+	if (axis != Vector3::AXIS_Z) {
+		SWAP(x_axis, y_axis);
+
+		for (int i = 0; i < 4; i++) {
+			if (axis == Vector3::AXIS_Y) {
+				vertices[i].y = -vertices[i].y;
+			} else if (axis == Vector3::AXIS_X) {
+				vertices[i].x = -vertices[i].x;
+			}
+		}
+	}
+
+	static const int indices[6] = {
+		0, 1, 2,
+		0, 2, 3
+	};
+
+	for (int j = 0; j < 6; j++) {
+		int i = indices[j];
+		Vector3 vtx;
+		vtx[x_axis] = vertices[i][0];
+		vtx[y_axis] = vertices[i][1];
+		facesw[j] = vtx;
+	}
+
+	facesw = PoolVector<Vector3>::Write();
+
+	triangle_mesh = Ref<TriangleMesh>(memnew(TriangleMesh));
+	triangle_mesh->create(faces);
+
+	return triangle_mesh;
+}
+
 void SpriteBase3D::set_draw_flag(DrawFlags p_flag, bool p_enable) {
 
 	ERR_FAIL_INDEX(p_flag, FLAG_MAX);
@@ -255,6 +318,7 @@ void SpriteBase3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_alpha_cut_mode"), &SpriteBase3D::get_alpha_cut_mode);
 
 	ClassDB::bind_method(D_METHOD("get_item_rect"), &SpriteBase3D::get_item_rect);
+	ClassDB::bind_method(D_METHOD("generate_triangle_mesh"), &SpriteBase3D::generate_triangle_mesh);
 
 	ClassDB::bind_method(D_METHOD("_queue_update"), &SpriteBase3D::_queue_update);
 	ClassDB::bind_method(D_METHOD("_im_update"), &SpriteBase3D::_im_update);
@@ -901,7 +965,7 @@ Rect2 AnimatedSprite3D::get_item_rect() const {
 		return Rect2(0, 0, 1, 1);
 	Size2i s = t->get_size();
 
-	Point2 ofs = offset;
+	Point2 ofs = get_offset();
 	if (centered)
 		ofs -= s / 2;
 
diff --git a/scene/3d/sprite_3d.h b/scene/3d/sprite_3d.h
index 23e1d96b4b..a4705a8970 100644
--- a/scene/3d/sprite_3d.h
+++ b/scene/3d/sprite_3d.h
@@ -38,6 +38,8 @@ class SpriteBase3D : public GeometryInstance {
 
 	GDCLASS(SpriteBase3D, GeometryInstance);
 
+	mutable Ref<TriangleMesh> triangle_mesh; //cached
+
 public:
 	enum DrawFlags {
 		FLAG_TRANSPARENT,
@@ -133,6 +135,7 @@ public:
 
 	virtual AABB get_aabb() const;
 	virtual PoolVector<Face3> get_faces(uint32_t p_usage_flags) const;
+	Ref<TriangleMesh> generate_triangle_mesh() const;
 
 	SpriteBase3D();
 	~SpriteBase3D();
@@ -192,7 +195,6 @@ class AnimatedSprite3D : public SpriteBase3D {
 	int frame;
 
 	bool centered;
-	Point2 offset;
 
 	float timeout;
 
diff --git a/scene/resources/primitive_meshes.cpp b/scene/resources/primitive_meshes.cpp
index 50673d0818..28aa6f1aa7 100644
--- a/scene/resources/primitive_meshes.cpp
+++ b/scene/resources/primitive_meshes.cpp
@@ -1352,10 +1352,10 @@ void QuadMesh::_create_mesh_array(Array &p_arr) const {
 	PoolVector<float> tangents;
 	PoolVector<Vector2> uvs;
 
-	faces.resize(4);
-	normals.resize(4);
-	tangents.resize(4 * 4);
-	uvs.resize(4);
+	faces.resize(6);
+	normals.resize(6);
+	tangents.resize(6 * 4);
+	uvs.resize(6);
 
 	Vector2 _size = Vector2(size.x / 2.0f, size.y / 2.0f);
 
@@ -1366,9 +1366,15 @@ void QuadMesh::_create_mesh_array(Array &p_arr) const {
 		Vector3(_size.x, -_size.y, 0),
 	};
 
-	for (int i = 0; i < 4; i++) {
+	static const int indices[6] = {
+		0, 1, 2,
+		0, 2, 3
+	};
+
+	for (int i = 0; i < 6; i++) {
 
-		faces.set(i, quad_faces[i]);
+		int j = indices[i];
+		faces.set(i, quad_faces[j]);
 		normals.set(i, Vector3(0, 0, 1));
 		tangents.set(i * 4 + 0, 1.0);
 		tangents.set(i * 4 + 1, 0.0);
@@ -1382,14 +1388,14 @@ void QuadMesh::_create_mesh_array(Array &p_arr) const {
 			Vector2(1, 1),
 		};
 
-		uvs.set(i, quad_uv[i]);
+		uvs.set(i, quad_uv[j]);
 	}
 
 	p_arr[VS::ARRAY_VERTEX] = faces;
 	p_arr[VS::ARRAY_NORMAL] = normals;
 	p_arr[VS::ARRAY_TANGENT] = tangents;
 	p_arr[VS::ARRAY_TEX_UV] = uvs;
-};
+}
 
 void QuadMesh::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_size", "size"), &QuadMesh::set_size);
@@ -1398,7 +1404,7 @@ void QuadMesh::_bind_methods() {
 }
 
 QuadMesh::QuadMesh() {
-	primitive_type = PRIMITIVE_TRIANGLE_FAN;
+	primitive_type = PRIMITIVE_TRIANGLES;
 	size = Size2(1.0, 1.0);
 }