VAT Render Quality Tiers¶
How to pick the right VAT shader tier for your target hardware and agent count.
When to read this¶
- You have already baked at least one VAT prefab and want to understand the quality vs. cost trade.
- You are targeting mobile and need to know which tier to use for the crowd.
- You are building a hero shot or marketing screenshot and want the most detailed look.
Concept¶
A VAT bake produces a material by default, and that material is assigned one of three render tier shaders. (Untick Create VAT Material in the Output section and the bake writes the VAT asset alone. Prefab output is then blocked, since a VAT prefab needs a linked material.) The tier controls lighting quality, which surface maps are supported, and how much the shader costs per agent. You choose the tier by selecting a Bake Preset in the VAT Baker, and the preset sets the sample rate, normal-bake flag, and the tier shader together.
Switching tiers later means rebaking with a different preset (or re-running the baker in update mode). When you switch to a lower tier, the baker clears surface map keywords the new shader no longer exposes, so none linger on the regenerated material.
Tier comparison¶
| Tier | Shader | Lighting | Surface maps | Relative cost | Best for |
|---|---|---|---|---|---|
| Mobile | Massive Swarm System/Swarm VAT/Mobile |
Half-Lambert + SH ambient | Base map only (no normal, metallic, occlusion, emission) | Lowest | 1000+ agents on-device |
| Standard | Massive Swarm System/Swarm VAT/Standard |
Main directional + soft shadows + SH ambient + reflection probes / skybox | Normal, metallic/ |
Medium | Hundreds of agents on desktop |
| High | Massive Swarm System/Swarm VAT/High |
Standard plus dynamic point/spot lights and additional-light shadows | Same as Standard | Highest | Small counts, hero shots, screenshots |
Standard is the default. Mobile has the fewest shader variants and compiles to the shortest forward-lit path: no additional lights, no shadow receives, no PBR surface maps.
How to choose¶
Use Mobile when the agent is part of the main crowd on a mobile build, or when you are hitting a GPU bottleneck at high agent counts on any platform. The shading is flatter (agents baked without normals are lit against an upward-facing default normal via half-Lambert, giving a uniformly top-lit look) but at crowd distance the difference is invisible.
Use Standard for most desktop projects. It gives full PBR shading (normal map, metallic/smoothness, occlusion, emission) lit by the main directional light with soft shadows, and reflects the skybox and reflection probes so metallic surfaces read as metal. It holds up to a few hundred agents on desktop.
Use High for close-range characters, cinematic hero shots, or screenshots where you want dynamic point and spot lights with their own shadows. High compiles many more shader variants than Standard. It is not meant for the crowd.
High tier on mobile build targets
The baker warns when the active build target is Android or iOS and the selected preset is High. High compiles per-pixel additional lights and many shader variants, which is heavy for an on-device crowd. Use Mobile or Standard for on-device agents and keep High for desktop or marketing captures.
Bake presets¶
The built-in presets are listed in the Bake Preset dropdown inside the VAT Baker, ordered from lowest to highest quality:
| Preset | Description |
|---|---|
| Mobile | Cheapest tier for the big crowd. Skips the normal texture, so shading is flatter at distance, the right trade for 1000+ swarms and on-device builds. |
| Standard | Balanced default. Full surface detail (normal, metallic, occlusion) lit by the main light with soft shadows. Good for hundreds of agents on desktop. |
| High | Showcase tier. Adds dynamic point and spot lights plus their shadows on top of Standard. For hero shots and small counts. |
Each preset selects the matching tier shader and sets the sample rate and normal-bake flag to values appropriate for that tier. You can override sample rate and normal-bake in Advanced mode after selecting a preset.
Generated materials have GPU instancing enabled automatically. The VAT shaders need it: every agent's animation state is pushed through a per-instance property block, and instancing is what lets a thousand of those share one material and one draw path.
Camera visibility LOD and normals¶
When Enable VAT Quality LOD is on in SwarmSettings, each agent's VAT shader quality follows whether the agent is being rendered at all, not its simulation importance tier. An agent in the camera frustum renders at full quality regardless of how far it is from its target. So does an agent outside the frustum that Unity still draws because it casts a visible shadow: a silhouette on the ground has to deform correctly or the shadow gives the trick away. Cheap quality is for agents nothing is drawing.
What the shader drops at cheap quality depends on which render tier you are using:
- Frame interpolation is disabled on all three shaders.
- Per-vertex baked normal (from the normal texture): Standard and High keep the baked normal so agents stay correctly shaded when they come back into view. Mobile drops the tap to save bandwidth, one position read per vertex instead of two. This only shows on a Mobile material that has a normal texture at all, and the stock Mobile preset bakes none, so a stock Mobile agent looks the same either way.
- Per-pixel normal-map detail (the surface
Normal Maptexture) is static and does not change with visibility. It is always on when the_NORMALMAPkeyword is enabled and always off when it is not; the quality LOD does not gate it. - All three shaders snap to the dominant walk/run clip instead of blending two clips.
The visual result: anything the camera or a shadow shows you renders at full quality. Standard and High stay correctly shaded out of view. Mobile is already the flatter tier by design, so what it saves here is a vertex read, not a look you would notice.
Shader name reference¶
| Tier | Full shader name |
|---|---|
| Mobile | Massive Swarm System/Swarm VAT/Mobile |
| Standard | Massive Swarm System/Swarm VAT/Standard |
| High | Massive Swarm System/Swarm VAT/High |
Related¶
- Animation: full VAT bake workflow and baker field reference
- Performance: mobile optimization priorities and Importance LOD tuning
- Swarm Settings: Enable VAT Quality LOD and camera-visibility animation settings