Smart Auto
Smart Auto is the recommended way to choose generated instance layouts in InstanceForge.
It follows a practical rule: prefer ISM first, use Split ISM before HISM, and choose HISM only when it clearly wins.
Recommended setup
Use this setup for normal production work:
Target: Auto
Auto Strategy: Smart Prefer ISM
Smart Auto Preset: Balanced
Original Handling: Hide originals after buildBalanced is the recommended default.
Simple Threshold vs Smart Prefer ISM
| Strategy | Behavior |
|---|---|
Simple Threshold | Chooses HISM when the group count is greater than or equal to the threshold. Otherwise chooses ISM. |
Smart Prefer ISM | Scores Single ISM, Split ISM, and HISM using group metadata and tuning settings. |
Smart Prefer ISM is usually better for mixed production scenes because it avoids blindly converting every large group to HISM.
What Smart Auto can choose
| Result | Meaning |
|---|---|
Single ISM | One ISM component for a compact/simple group. |
Split ISM | Multiple ISM components split by spatial clusters. |
HISM | One HISM component when HISM wins clearly. |
Reading decisions
Look at the selected group row in the Build Plan.
Check:
- instance count;
- resolved target;
- draw-call impact;
- tooltip or diagnostic reason;
- Smart Auto preset and margin.
Use these diagnostics before forcing manual overrides.
Scoring inputs
Smart Auto can consider metadata such as:
- instance count;
- material slot count;
- mobility;
- spatial spread;
- split cluster count;
- LOD count and LOD0 triangle/vertex data when available;
- collision and shadow signals;
- Nanite or LOD screen-size related data when available.
When metadata is missing, Smart Auto uses conservative fallbacks and surfaces hints.
Presets
| Preset | HISM Win Margin | Use case |
|---|---|---|
Conservative | 35% | Strongly prefers ISM/Split ISM. |
Balanced | 25% | Recommended default. |
Aggressive | 15% | More willing to choose HISM. |
Custom | User-defined | Used when you edit the margin manually. |
HISM Win Margin % controls how much better HISM must score compared with the best ISM path.
Important settings
| Setting | Purpose |
|---|---|
HISM Fallback Count | Uses HISM when Split ISM is not practical for very large groups. |
Allow Spatial Split ISM | Allows distributed groups to become multiple compact ISM clusters. |
Cluster Radius | Controls spatial cluster size for Split ISM. |
Min Instances/Cluster | Prevents tiny clusters. |
Max Clusters/Group | Prevents too many generated components. |
HISM Win Margin % | Required HISM score advantage over the best ISM path. |
Typical examples
| Scene pattern | Common result |
|---|---|
| Small compact group | Single ISM |
| Large distributed group | Split ISM |
| Large static heavy group | HISM if margin passes |
| Movable group | Usually ISM or Split ISM unless manually forced |
Manual overrides
Use manual overrides only when you understand why the automatic decision is not suitable.
Manual HISM on movable groups can produce warnings.
Next steps
Continue to Plan and Build or Configuration Reference.