Helper tool to create geometry. The [SurfaceTool] is used to construct a [Mesh] by specifying vertex attributes individually. It can be used to construct a [Mesh] from a script. All properties except indices need to be added before calling [method add_vertex]. For example, to add vertex colors and UVs: [codeblock] var st = SurfaceTool.new() st.begin(Mesh.PRIMITIVE_TRIANGLES) st.set_color(Color(1, 0, 0)) st.set_uv(Vector2(0, 0)) st.set_vertex(Vector3(0, 0, 0)) [/codeblock] The above [SurfaceTool] now contains one vertex of a triangle which has a UV coordinate and a specified [Color]. If another vertex were added without calling [method set_uv] or [method set_color], then the last values would be used. Vertex attributes must be passed [b]before[/b] calling [method add_vertex]. Failure to do so will result in an error when committing the vertex information to a mesh. Additionally, the attributes used before the first vertex is added determine the format of the mesh. For example, if you only add UVs to the first vertex, you cannot add color to any of the subsequent vertices. See also [ArrayMesh], [ImmediateGeometry3D] and [MeshDataTool] for procedural geometry generation. [b]Note:[/b] Godot uses clockwise [url=https://learnopengl.com/Advanced-OpenGL/Face-culling]winding order[/url] for front faces of triangle primitive modes. https://godotengine.org/asset-library/asset/676 Adds an index to index array if you are using indexed vertices. Does not need to be called before adding vertices. Inserts a triangle fan made of array data into [Mesh] being constructed. Requires the primitive type be set to [constant Mesh.PRIMITIVE_TRIANGLES]. Specifies the position of current vertex. Should be called after specifying other vertex properties (e.g. Color, UV). Append vertices from a given [Mesh] surface onto the current vertex array with specified [Transform]. Called before adding any vertices. Takes the primitive type as an argument (e.g. [constant Mesh.PRIMITIVE_TRIANGLES]). Clear all information passed into the surface tool so far. Returns a constructed [ArrayMesh] from current information passed in. If an existing [ArrayMesh] is passed in as an argument, will add an extra surface to the existing [ArrayMesh]. [b]FIXME:[/b] Document possible values for [code]flags[/code], it changed in 4.0. Likely some combinations of [enum Mesh.ArrayFormat]. Commits the data to the same format used by [method ArrayMesh.add_surface_from_arrays]. This way you can further process the mesh data using the [ArrayMesh] API. Creates a vertex array from an existing [Mesh]. Creates a vertex array from the specified blend shape of an existing [Mesh]. This can be used to extract a specific pose from a blend shape. Removes the index array by expanding the vertex array. Generates normals from vertices so you do not have to do it manually. If [code]flip[/code] is [code]true[/code], the resulting normals will be inverted. [method generate_normals] should be called [i]after[/i] generating geometry and [i]before[/i] committing the mesh using [method commit] or [method commit_to_arrays]. [b]Note:[/b] [method generate_normals] only works if the primitive type to be set to [constant Mesh.PRIMITIVE_TRIANGLES]. Generates a tangent vector for each vertex. Requires that each vertex have UVs and normals set already. Shrinks the vertex array by creating an index array (avoids reusing vertices). Specifies an array of bones for the next vertex to use. [code]bones[/code] must contain 4 integers. Specifies a [Color] for the next vertex to use. [b]Note:[/b] The material must have [member BaseMaterial3D.vertex_color_use_as_albedo] enabled for the vertex color to be visible. Sets [Material] to be used by the [Mesh] you are constructing. Specifies a normal for the next vertex to use. Specifies whether the current vertex (if using only vertex arrays) or current index (if also using index arrays) should use smooth normals for normal calculation. Specifies a tangent for the next vertex to use. Specifies a set of UV coordinates to use for the next vertex. Specifies an optional second set of UV coordinates to use for the next vertex. Specifies weight values for next vertex to use. [code]weights[/code] must contain 4 values.