The Create Instances operation optimizes scene performance by replacing identical meshes with instanced versions. This technique reduces the number of individual draw calls in the scene, resulting in improved rendering performance and memory usage.

This operation identifies actors in the scene that use the same mesh and material configurations. If a certain number of identical meshes are found (based on the user-defined threshold), they are replaced with Instanced Static Meshes (ISM) or Hierarchical Instanced Static Meshes (HISM). This operation is ideal for scenes with repeated assets, such as foliage, architectural elements, or repeated props.

Dependencies

Run Create Instances after operations like Hierarchy Merge and Replace Duplicates to ensure that all potential instances are captured. This operation can significantly reduce the number of unique actors in the scene, especially after removing duplicates or consolidating groups.

Best Practices

• Minimum Instances: Adjust the MinimumInstances setting to control how many identical meshes must exist before instancing occurs. A higher value is suitable for dense scenes like forests or cities.
• Optimize Repeated Assets: Use this operation to optimize scenes with many identical props, decorations, or architectural elements. This reduces draw calls, leading to better performance.
• Manual Review: After instancing, review the scene to ensure that no essential actors were incorrectly instanced, as this operation changes the mesh representation but retains the original actor locations.

Considerations

• Performance Impact: For large scenes, the instancing process might temporarily increase CPU and memory usage. Ensure you have sufficient system resources available, or consider processing per level.