godot/doc/classes/MultiMesh.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="MultiMesh" inherits="Resource" version="4.0">
	<brief_description>
		Provides high-performance mesh instancing.
	</brief_description>
	<description>
		MultiMesh provides low-level mesh instancing. Drawing thousands of [MeshInstance3D] nodes can be slow, since each object is submitted to the GPU then drawn individually.
		MultiMesh is much faster as it can draw thousands of instances with a single draw call, resulting in less API overhead.
		As a drawback, if the instances are too far away from each other, performance may be reduced as every single instance will always render (they are spatially indexed as one, for the whole object).
		Since instances may have any behavior, the AABB used for visibility must be provided by the user.
	</description>
	<tutorials>
		<link title="Animating thousands of fish with MultiMeshInstance">https://docs.godotengine.org/en/latest/tutorials/performance/vertex_animation/animating_thousands_of_fish.html</link>
		<link title="Optimization using MultiMeshes">https://docs.godotengine.org/en/latest/tutorials/performance/using_multimesh.html</link>
	</tutorials>
	<methods>
		<method name="get_aabb" qualifiers="const">
			<return type="AABB" />
			<description>
				Returns the visibility axis-aligned bounding box in local space. See also [method VisualInstance3D.get_transformed_aabb].
			</description>
		</method>
		<method name="get_instance_color" qualifiers="const">
			<return type="Color" />
			<argument index="0" name="instance" type="int" />
			<description>
				Gets a specific instance's color.
			</description>
		</method>
		<method name="get_instance_custom_data" qualifiers="const">
			<return type="Color" />
			<argument index="0" name="instance" type="int" />
			<description>
				Returns the custom data that has been set for a specific instance.
			</description>
		</method>
		<method name="get_instance_transform" qualifiers="const">
			<return type="Transform3D" />
			<argument index="0" name="instance" type="int" />
			<description>
				Returns the [Transform3D] of a specific instance.
			</description>
		</method>
		<method name="get_instance_transform_2d" qualifiers="const">
			<return type="Transform2D" />
			<argument index="0" name="instance" type="int" />
			<description>
				Returns the [Transform2D] of a specific instance.
			</description>
		</method>
		<method name="set_instance_color">
			<return type="void" />
			<argument index="0" name="instance" type="int" />
			<argument index="1" name="color" type="Color" />
			<description>
				Sets the color of a specific instance by [i]multiplying[/i] the mesh's existing vertex colors.
				For the color to take effect, ensure that [member use_colors] is [code]true[/code] on the [MultiMesh] and [member BaseMaterial3D.vertex_color_use_as_albedo] is [code]true[/code] on the material.
			</description>
		</method>
		<method name="set_instance_custom_data">
			<return type="void" />
			<argument index="0" name="instance" type="int" />
			<argument index="1" name="custom_data" type="Color" />
			<description>
				Sets custom data for a specific instance. Although [Color] is used, it is just a container for 4 floating point numbers.
				For the custom data to be used, ensure that [member use_custom_data] is [code]true[/code].
			</description>
		</method>
		<method name="set_instance_transform">
			<return type="void" />
			<argument index="0" name="instance" type="int" />
			<argument index="1" name="transform" type="Transform3D" />
			<description>
				Sets the [Transform3D] for a specific instance.
			</description>
		</method>
		<method name="set_instance_transform_2d">
			<return type="void" />
			<argument index="0" name="instance" type="int" />
			<argument index="1" name="transform" type="Transform2D" />
			<description>
				Sets the [Transform2D] for a specific instance.
			</description>
		</method>
	</methods>
	<members>
		<member name="buffer" type="PackedFloat32Array" setter="set_buffer" getter="get_buffer" default="PackedFloat32Array()">
		</member>
		<member name="color_array" type="PackedColorArray" setter="_set_color_array" getter="_get_color_array">
		</member>
		<member name="custom_data_array" type="PackedColorArray" setter="_set_custom_data_array" getter="_get_custom_data_array">
		</member>
		<member name="instance_count" type="int" setter="set_instance_count" getter="get_instance_count" default="0">
			Number of instances that will get drawn. This clears and (re)sizes the buffers. By default, all instances are drawn but you can limit this with [member visible_instance_count].
		</member>
		<member name="mesh" type="Mesh" setter="set_mesh" getter="get_mesh">
			Mesh to be drawn.
		</member>
		<member name="transform_2d_array" type="PackedVector2Array" setter="_set_transform_2d_array" getter="_get_transform_2d_array">
		</member>
		<member name="transform_array" type="PackedVector3Array" setter="_set_transform_array" getter="_get_transform_array">
		</member>
		<member name="transform_format" type="int" setter="set_transform_format" getter="get_transform_format" enum="MultiMesh.TransformFormat" default="0">
			Format of transform used to transform mesh, either 2D or 3D.
		</member>
		<member name="use_colors" type="bool" setter="set_use_colors" getter="is_using_colors" default="false">
			If [code]true[/code], the [MultiMesh] will use color data (see [member color_array]).
		</member>
		<member name="use_custom_data" type="bool" setter="set_use_custom_data" getter="is_using_custom_data" default="false">
			If [code]true[/code], the [MultiMesh] will use custom data (see [member custom_data_array]).
		</member>
		<member name="visible_instance_count" type="int" setter="set_visible_instance_count" getter="get_visible_instance_count" default="-1">
			Limits the number of instances drawn, -1 draws all instances. Changing this does not change the sizes of the buffers.
		</member>
	</members>
	<constants>
		<constant name="TRANSFORM_2D" value="0" enum="TransformFormat">
			Use this when using 2D transforms.
		</constant>
		<constant name="TRANSFORM_3D" value="1" enum="TransformFormat">
			Use this when using 3D transforms.
		</constant>
	</constants>
</class>