Memory Usage & Render Performance

This article dives into the various stat commands available within the plugin.

A common topic of discussion when it comes to solutions for terrain rendering within Unreal Engine is how performance compares to the stock Landscape solution. Unfortunately, it is hard to give a concrete answer to exactly how performance compares. Because of the amount of moving parts involved, we would rather provide the tools needed for users to make an educate decision after testing ffor their usecase.

Within the plugin, we have several different stat commands to help you nail down the resources used by your worlds. These stats will vary dramatically depending on the (combinations of) nodes used within your MetaGraph.

1. CPU - stat voxel

The first statgroup, useful for quickly determining where the plugin is spending CPU time, is stat voxel. This is a good starting point when experiencing hitching or lag spikes from the game thread.

This statistic reads back performance counters from voxel tasks. These tasks only exist when the world is actively generating. Because of this, these numbers are generally only useful when the world was refreshed, or when the camera is moving.

2. Debug and Rendering - stat voxelcounters

stat voxelcounters brings up a display of general counters related to Voxel Plugin functionality.

• Num Foliage Instances is the current amount of instances generated by the foliage nodes within your graph. This counts all active instances, including culled instances. More statistics on foliage rendering can be found using the stock stat foliage and stat rhi commands.

• Detail Textures Num is the amount of unique texture resources that have been created by your graph. This includes some amount of indirection textures required for detail textures to work.

• Voxel Material Instances Used is the amount of unique material instances created for your active terrain chunks.

• Num Subsystems is the number of unique subsystems running within the plugin at this time.

• Voxel Material Instances Pool should not be a huge number (>1k). If it is, post a support query on the Voxel Plugin Discord.

3. (V)RAM Usage - stat voxelmemory

stat voxelmemory reports how much memory is currently being used by the various plugin systems.

This is fun because as it turns out these stats are sometimes RAM and sometimes VRAM :)