🖥️ Client-Side Anisotropic Chunk Mesh Prioritization (MC 26.3)
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1. Official Infobox Table
| Parameter | Technical Details |
|---|---|
| Subsystem Name | Anisotropic Chunk Mesh Prioritization |
| Minecraft Anchor | MC 26.3 |
| Java Implementation | net.vanillaoutsider.velocityrender.math.AnisotropicDistanceHelper |
| Client Polling Mixin | net.vanillaoutsider.velocityrender.client.mixin.SectionTaskDynamicQueueMixin |
| Vanilla Target Class | net.minecraft.client.renderer.chunk.SectionTaskDynamicQueue |
| Target Method | poll() |
| Redirect Call | Lnet/minecraft/core/BlockPos;distToCenterSqr(Lnet/minecraft/core/Position;)D |
| Controlling GameRules | velocityrender:enabled, velocityrender:forward_lead_multiplier, velocityrender:min_speed_threshold_pct |
| Default Activation Speed | $0.20\text{ blocks/tick} = 4.0\text{ m/s}$ |
| Maximum Lead Offset | $256.0\text{ blocks}$ (16 Chunks ahead) |
2. Step-by-Step Player Workflow & Behavior
+----------------------------------------+
| Player Traversal (Walking / Running / |
| Riding Horse / Elytra Flight) |
+----------------------------------------+
|
v
[ ClientTickEvents.END_CLIENT_TICK ]
|
v
[ ClientVelocityTracker.clientTick() ]
/ \
(Speed < 0.20 b/t) (Speed >= 0.20 b/t)
| |
v v
+-----------------------+ +-----------------------------+
| activeBias = false | | activeBias = true |
| cachedLeadOffset = 0 | | Compute normalized dx,dy,dz |
| Vanilla Radial Sphere | | cachedLeadOffset = v * 16 |
+-----------------------+ +-----------------------------+
| |
+--------------------+---------------------+
|
v
[ SectionTaskDynamicQueue.poll() ]
|
v
[ calculateBiasedDistanceSqr() ]
|
Forward terrain scored lower!
Compiled and rendered FIRST on screen!- Stationary & Walking Phase ($s < 0.20\text{ b/t}$):
- The velocity tracking engine detects normal movement below threshold.
ClientVelocityTracker.activeBiasremainsfalse.- Chunk compile tasks are sorted by standard radial Euclidean distance.
- Accelerated Travel Phase ($0.20 \le s < 0.50\text{ b/t}$):
- When sprinting or galloping on a horse, velocity reaches $0.25 - 0.45\text{ b/t}$.
- Directional biasing activates, extending forward lead offset between $32$ and $64$ blocks ahead.
- Terrain directly in front of the horse or player appears seamlessly without visible draw-in.
- Hyper-Velocity Phase ($s \ge 0.50\text{ b/t}$):
- Rocket-boosted Elytra flight, ice boating on blue ice, or minecart hyper-rails ($s = 1.0 - 2.5\text{ b/t}$).
- Maximum directional lead offset clamps up to $256.0\text{ blocks}$ ($16$ chunks ahead).
- The render scheduler prioritizes an aerodynamic cone centered along the player's flight vector, eliminating void walls and abrupt mountain pop-in.
3. Mathematical Foundations & Equations
Exponential Moving Average (EMA) Velocity Smoothing
Raw entity delta coordinates $\Delta x, \Delta y, \Delta z$ can jitter during rapid mouse movement. An exponential moving average with smoothing constant $\alpha = 0.65$ eliminates noise while ensuring instant physical response:
$$\vec{v}{\text{eff}} = \begin{cases} \Delta\vec{P} & \text{if } |\Delta\vec{P}| > 0.001 \ \vec{v}{\text{raw}} & \text{otherwise} \end{cases}$$
$$\vec{v}{\text{smooth}} = \alpha \cdot \vec{v}{\text{eff}} + (1.0 - \alpha) \cdot \vec{v}_{\text{smooth}}, \quad \alpha = 0.65$$
Speed Magnitude & Unit Vector Normalization
$$s = |\vec{v}_{\text{smooth}}| = \sqrt{v_x^2 + v_y^2 + v_z^2}$$
$$\vec{d}{\text{norm}} = \begin{cases} \frac{\vec{v}{\text{smooth}}}{s} & \text{if } s > 10^{-4} \ \vec{0} & \text{otherwise} \end{cases}$$
Anisotropic Directional Dot-Product Distance Bias
For each chunk render section origin $\vec{P}{\text{section}}$ relative to camera position $\vec{P}{\text{cam}}$:
$$\Delta\vec{P} = (\vec{P}{\text{section}} + 0.5) - \vec{P}{\text{cam}}$$
$$\text{EuclideanDistSqr} = \Delta x^2 + \Delta y^2 + \Delta z^2$$
$$\text{DotProduct} = \vec{d}_{\text{norm}} \cdot \Delta\vec{P} = d_x \Delta x + d_y \Delta y + d_z \Delta z$$
$$\text{LeadOffset} = \min\left(256.0,, s \times 16.0 \times \frac{\text{leadMultiplier}}{100}\right)$$
$$\text{BiasedDistSqr} = \max\left(0.0,, \text{EuclideanDistSqr} - 2.0 \cdot \text{DotProduct} \cdot \text{LeadOffset}\right)$$
When a chunk section lies ahead ($\text{DotProduct} > 0$), its distance score is reduced by up to $2 \cdot \text{DotProduct} \cdot \text{LeadOffset}$, placing it at the front of the compile queue. When behind ($\text{DotProduct} < 0$), the subtraction becomes an addition, deferring rear compilation.
4. Visual ASCII Diagram: Radial Sorting vs Anisotropic Cone
VANILLA RADIAL SORTING ANISOTROPIC VELOCITY BIAS
(Equal priority in all directions) (Elongated aerodynamic cone ahead)
. - ~ ~ - . . - ~ ~ - .
. . . : .
. . . : .
. ^ . . +----+----+ .
. | . . | CHUNK | .
. <-- [P] --> . . | AHEAD 1 | .
. | . . +----+----+ .
. v . . | CHUNK | .
. . . | AHEAD 2 | .
. . . +----+----+ .
. - ~ ~ - . . | .
. - ~ ~ [P] ~ ~ - .
(v)5. Hot-Path Memory & Volatile State Schema
To guarantee $O(1)$ lock-free access across render worker threads polling at multi-gigahertz rates:
HotPathCache (volatile in ClientVelocityTracker):
├── activeBias: boolean // Gating boolean flag
├── cachedNormDx: double // Normalized X flight vector component
├── cachedNormDy: double // Normalized Y flight vector component
├── cachedNormDz: double // Normalized Z flight vector component
└── cachedLeadOffset: double // Clamped lookahead reach (0.0 to 256.0)6. Exhaustive Reference Tables
| Travel Mode | Velocity ($s$) | Velocity (m/s) | Active Bias | Lead Offset | Meshing Prioritization Reach |
|---|---|---|---|---|---|
| Idle / Stationary | $0.00\text{ b/t}$ | $0.0\text{ m/s}$ | false | $0.0\text{ blocks}$ | Standard vanilla radial meshing |
| Walking | $0.11\text{ b/t}$ | $2.2\text{ m/s}$ | false | $0.0\text{ blocks}$ | Standard vanilla radial meshing |
| Sprinting | $0.28\text{ b/t}$ | $5.6\text{ m/s}$ | true | $44.8\text{ blocks}$ | Forward $2 - 3$ chunk bias |
| Horse Gallop | $0.45\text{ b/t}$ | $9.0\text{ m/s}$ | true | $72.0\text{ blocks}$ | Forward $4 - 5$ chunk bias |
| Elytra Glide | $1.20\text{ b/t}$ | $24.0\text{ m/s}$ | true | $192.0\text{ blocks}$ | Forward $12$ chunk aerodynamic cone |
| Elytra Firework Rocket | $1.80\text{ b/t}$ | $36.0\text{ m/s}$ | true | $256.0\text{ blocks}$ (Clamped) | Maximum $16$ chunk forward priority |
| Ice Boat Hyperway | $2.40\text{ b/t}$ | $48.0\text{ m/s}$ | true | $256.0\text{ blocks}$ (Clamped) | Maximum $16$ chunk forward priority |
7. Developer & Mixin Hooks
Mixin Implementation Snippet
// Target Class: SectionTaskDynamicQueue
@Mixin(SectionTaskDynamicQueue.class)
public abstract class SectionTaskDynamicQueueMixin {
@Redirect(
method = "poll",
at = @At(
value = "INVOKE",
target = "Lnet/minecraft/core/BlockPos;distToCenterSqr(Lnet/minecraft/core/Position;)D"
)
)
private double youRunFast$biasedDistance(BlockPos origin, Position cameraPos) {
return AnisotropicDistanceHelper.calculateBiasedDistanceSqr(origin, cameraPos);
}
}Key Java Method Signatures
AnisotropicDistanceHelper.calculateBiasedDistanceSqr(BlockPos origin, Position cameraPos): Fast-path method executed per candidate section.ClientVelocityTracker.clientTick(Minecraft client): Updates EMA velocity and volatile cache every client tick.ClientVelocityTracker.setLeadMultiplier(double value): Dynamically tunes lookahead stretch factor.