How do layerCullDistances work?

A float[32] indexed by layer. Each entry sets the max render distance for renderers on that layer. Value 0 = use camera’s far plane (no per-layer override). Non-zero limits that layer’s rendering to that distance from camera.

Why aren't my distances honored?

You assigned to a new array variable, not the camera’s. Must assign back: var d = cam.layerCullDistances; d[8] = 100; cam.layerCullDistances = d. Reading returns a copy; writing requires reassignment.

What about layerCullSpherical?

Bool flag: true uses spherical distance from camera position; false uses planar distance from near plane. Default false (planar). Set true for symmetric culling around the camera.

Fix: Unity Camera Layer Cull Distances Not Applied

Quick answer: cam.layerCullDistances returns a copy. Modify and assign back: var d = cam.layerCullDistances; d[layer] = 100; cam.layerCullDistances = d.

You want grass on layer 8 to cull at 100 units. Setting cam.layerCullDistances[8] = 100 compiles but has no effect at runtime. The property returns a copy of the internal array; mutating the copy doesn’t affect the camera.

Reassignment Required

int grassLayer = LayerMask.NameToLayer("Grass");

float[] distances = cam.layerCullDistances;
distances[grassLayer] = 100f;
cam.layerCullDistances = distances;

The read returns a copy. Modify the copy; write it back. The camera adopts the modified array.

Spherical vs Planar

cam.layerCullSpherical = true;

Spherical means distance measured from camera position (a sphere). Planar means distance perpendicular to the camera plane (a slab). Spherical is more intuitive; default is false (planar) for legacy reasons.

Per-Layer Tuning

float[] d = new float[32];   // 32 layers max
d[LayerMask.NameToLayer("Grass")] = 50;
d[LayerMask.NameToLayer("SmallProps")] = 80;
d[LayerMask.NameToLayer("Buildings")] = 500;
// Layer 0 (Default) stays 0 = use far plane
cam.layerCullDistances = d;

Per-layer distances let you cull dense low-importance content close while keeping landmarks visible far.

Verifying

Walk away from a known grass instance. With cull set to 50, grass should disappear at 50 units while trees stay visible. Use the Scene view’s Show Stats to confirm renderers drop count at the threshold.

“layerCullDistances is a get-modify-set property. The copy-then-assign pattern is essential.”

Per-layer cull is a major perf win for outdoor scenes — dense grass at 30m, distinct objects at 200m+ — without dynamic LODs.