Optimization using MultiMeshes

using servers directly is the recommended optimization. When the amount of objects reach the hundreds of thousands or millions, none of these approaches are efficient anymore. Still, depending on the requirements, there is one more optimization possible.

MultiMeshes

MultiMesh is a single draw primitive that can draw up to millions of objects in one go. It’s extremely efficient because it uses the GPU hardware to do this (in OpenGL ES 2.0, it’s less efficient because there is no hardware support for it, though). screen or frustum culling possible for individual instances. This means, that millions of objects will be always or never drawn, depending on the visibility of the whole MultiMesh. It is possible to provide a custom visibility rect for them, but it will always be all-or-none visibility. If the objects are simple enough (just a couple of vertices), this is generally not much of a problem as most modern GPUs are optimized for this use case. A workaround is to create several MultiMeshes for different areas of the world. INSTANCE_ID or INSTANCE_CUSTOM built-in constants). For an example of animating thousands of objects in a MultiMesh, see the Animating thousands of fish tutorial. Information to the shader can be provided via textures (there are floating-point Image formats which are ideal for this). VisualServer.multimesh_set_as_bulk_array() function). This way, the array can be created with multiple threads, then set in one call, providing high cache efficiency. MultiMesh.visible_instance_count property. The typical workflow is to allocate the maximum amount of instances that will be used, then change the amount visible depending on how many are currently needed.

Multimesh example

Here is an example of using a MultiMesh from code. Languages other than GDScript may be more efficient for millions of objects, but for a few thousands, GDScript should be fine. GDScript C#

extends MultiMeshInstancefunc _ready():    # Create the multimesh.    multimesh = MultiMesh.new()    # Set the format first.    multimesh.transform_format = MultiMesh.TRANSFORM_3D    multimesh.color_format = MultiMesh.COLOR_NONE    multimesh.custom_data_format = MultiMesh.CUSTOM_DATA_NONE    # Then resize (otherwise, changing the format is not allowed).    multimesh.instance_count = 10000    # Maybe not all of them should be visible at first.    multimesh.visible_instance_count = 1000    # Set the transform of the instances.    for i in multimesh.visible_instance_count:        multimesh.set_instance_transform(i, Transform(Basis(), Vector3(i * 20, 0, 0)))

using Godot;using System;public class YourClassName : MultiMeshInstance{    public override void _Ready()    {        // Create the multimesh.        Multimesh = new MultiMesh();        // Set the format first.        Multimesh.TransformFormat = MultiMesh.TransformFormatEnum.Transform3d;        Multimesh.ColorFormat = MultiMesh.ColorFormatEnum.None;        Multimesh.CustomDataFormat = MultiMesh.CustomDataFormatEnum.None;        // Then resize (otherwise, changing the format is not allowed)        Multimesh.InstanceCount = 1000;        // Maybe not all of them should be visible at first.        Multimesh.VisibleInstanceCount = 1000;        // Set the transform of the instances.        for (int i = 0; i < Multimesh.VisibleInstanceCount; i++)        {            Multimesh.SetInstanceTransform(i, new Transform(Basis.Identity, new Vector3(i * 20, 0, 0)));        }    }}