Class reference
MultiMesh
Inherits Resource
Provides high-performance drawing of a mesh multiple times using GPU instancing.
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. Note: A MultiMesh is a single object, therefore the same maximum lights per object restriction applies. This means, that once the maximum lights are consumed by one or more instances, the rest of the MultiMesh instances will not receive any lighting. Note: Blend Shapes will be ignored if used in a MultiMesh.
Properties
PackedFloat32Array buffer = PackedFloat32Array()
PackedFloat32Array buffer = PackedFloat32Array()PackedColorArray color_array
PackedColorArray color_arrayAccessing this property is very slow. Use set_instance_color() and get_instance_color() instead.
Array containing each Color used by all instances of this mesh.
AABB custom_aabb = AABB(0, 0, 0, 0, 0, 0)
AABB custom_aabb = AABB(0, 0, 0, 0, 0, 0)Custom AABB for this MultiMesh resource. Setting this manually prevents costly runtime AABB recalculations.
PackedColorArray custom_data_array
PackedColorArray custom_data_arrayAccessing this property is very slow. Use set_instance_custom_data() and get_instance_custom_data() instead.
Array containing each custom data value used by all instances of this mesh, as a PackedColorArray.
int instance_count = 0
int instance_count = 0Number of instances that will get drawn. This clears and (re)sizes the buffers. Setting data format or flags afterwards will have no effect. By default, all instances are drawn but you can limit this with visible_instance_count.
Mesh mesh
Mesh meshMesh resource to be instanced. The looks of the individual instances can be modified using set_instance_color() and set_instance_custom_data().
int physics_interpolation_quality = 0
int physics_interpolation_quality = 0Choose whether to use an interpolation method that favors speed or quality. When using low physics tick rates (typically below 20) or high rates of object rotation, you may get better results from the high quality setting. Note: Fast quality does not equate to low quality. Except in the special cases mentioned above, the quality should be comparable to high quality.
PackedVector2Array transform_2d_array
PackedVector2Array transform_2d_arrayAccessing this property is very slow. Use set_instance_transform_2d() and get_instance_transform_2d() instead.
Array containing each Transform2D value used by all instances of this mesh, as a PackedVector2Array. Each transform is divided into 3 Vector2 values corresponding to the transforms' x, y, and origin.
PackedVector3Array transform_array
PackedVector3Array transform_arrayAccessing this property is very slow. Use set_instance_transform() and get_instance_transform() instead.
Array containing each Transform3D value used by all instances of this mesh, as a PackedVector3Array. Each transform is divided into 4 Vector3 values corresponding to the transforms' x, y, z, and origin.
int transform_format = 0
int transform_format = 0Format of transform used to transform mesh, either 2D or 3D.
bool use_colors = false
bool use_colors = falseIf true, the MultiMesh will use color data (see set_instance_color()). Can only be set when instance_count is 0 or less. This means that you need to call this method before setting the instance count, or temporarily reset it to 0.
bool use_custom_data = false
bool use_custom_data = falseIf true, the MultiMesh will use custom data (see set_instance_custom_data()). Can only be set when instance_count is 0 or less. This means that you need to call this method before setting the instance count, or temporarily reset it to 0.
int visible_instance_count = -1
int visible_instance_count = -1Limits the number of instances drawn, -1 draws all instances. Changing this does not change the sizes of the buffers.
Methods
AABB get_aabb() const
AABB get_aabb() constReturns the visibility axis-aligned bounding box in local space.
Color get_instance_color(int instance) const
Color get_instance_color(int instance) constGets a specific instance's color multiplier.
Color get_instance_custom_data(int instance) const
Color get_instance_custom_data(int instance) constReturns the custom data that has been set for a specific instance.
Transform3D get_instance_transform(int instance) const
Transform3D get_instance_transform(int instance) constReturns the Transform3D of a specific instance.
Transform2D get_instance_transform_2d(int instance) const
Transform2D get_instance_transform_2d(int instance) constReturns the Transform2D of a specific instance.
void reset_instance_physics_interpolation(int instance)
int instance)When using physics interpolation, this function allows you to prevent interpolation on an instance in the current physics tick. This allows you to move instances instantaneously, and should usually be used when initially placing an instance such as a bullet to prevent graphical glitches.
void set_buffer_interpolated(PackedFloat32Array buffer_curr, PackedFloat32Array buffer_prev)
PackedFloat32Array buffer_curr, PackedFloat32Array buffer_prev)An alternative to setting the buffer property, which can be used with physics interpolation. This method takes two arrays, and can set the data for the current and previous tick in one go. The renderer will automatically interpolate the data at each frame. This is useful for situations where the order of instances may change from physics tick to tick, such as particle systems. When the order of instances is coherent, the simpler alternative of setting buffer can still be used with interpolation.
void set_instance_color(int instance, Color color)
int instance, Color color)Sets the color of a specific instance by multiplying the mesh's existing vertex colors. This allows for different color tinting per instance. Note: Each component is stored in 32 bits in the Forward+ and Mobile rendering methods, but is packed into 16 bits in the Compatibility rendering method. For the color to take effect, ensure that use_colors is true on the MultiMesh and BaseMaterial3D.vertex_color_use_as_albedo is true on the material. If you intend to set an absolute color instead of tinting, make sure the material's albedo color is set to pure white (Color(1, 1, 1)).
void set_instance_custom_data(int instance, Color custom_data)
int instance, Color custom_data)Sets custom data for a specific instance. custom_data is a Color type only to contain 4 floating-point numbers. Note: Each number is stored in 32 bits in the Forward+ and Mobile rendering methods, but is packed into 16 bits in the Compatibility rendering method. For the custom data to be used, ensure that use_custom_data is true. This custom instance data has to be manually accessed in your custom shader using INSTANCE_CUSTOM.
void set_instance_transform(int instance, Transform3D transform)
int instance, Transform3D transform)Sets the Transform3D for a specific instance.
void set_instance_transform_2d(int instance, Transform2D transform)
int instance, Transform2D transform)Sets the Transform2D for a specific instance.
Constants
TRANSFORM_2D = 0
Use this when using 2D transforms.
TRANSFORM_3D = 1
Use this when using 3D transforms.
INTERP_QUALITY_FAST = 0
Always interpolate using Basis lerping, which can produce warping artifacts in some situations.
INTERP_QUALITY_HIGH = 1
Attempt to interpolate using Basis slerping (spherical linear interpolation) where possible, otherwise fall back to lerping.