Tier 3
Series 202
202F: The Material Batch
"Air Traffic Control handles a formation of planes as a single unit. If every plane files a separate flight plan, the radio frequency jams. In Unity, accessing `renderer.material` creates a unique "Flight Plan" (Material Instance) for that object, breaking Batching and killing the GPU."
The Concept: MaterialPropertyBlock
To change the color of 1000 objects efficiently, you cannot give them 1000 unique materials. You must use **MaterialPropertyBlocks** to override the properties of a shared material without breaking the batch.
* **Batching:** Unity combining multiple objects into one "Draw Call."
* **.material:** BAD. Creates a copy.
* **.sharedMaterial:** GOOD. Accesses the original.
* **Batching:** Unity combining multiple objects into one "Draw Call."
* **.material:** BAD. Creates a copy.
* **.sharedMaterial:** GOOD. Accesses the original.
Red Flag Detected
The AI Trap: "The Draw Call Jam"
You ask the AI: "Randomize the color of every enemy."
// AI-Generated Code: Graphics Killer
void Start() {
// Audit Fail: This creates a unique material copy for this object.
// If you have 100 enemies, you now have 100 extra Draw Calls.
GetComponent<Renderer>().material.color = Random.ColorHSV();
}
This is "Batch Breaking." The GPU can no longer draw these enemies together. Performance plummets as the CPU struggles to send 100 separate instructions to the video card.
Elite Telemetry
Research shows "Elite" teams achieve 15% faster lead times by keeping AI on a "very tight leash."
- Small Batches Solving one problem at a time prevents logic drift.
- Modular Design Localizing the "blast radius" of AI changes.
- Tight Loops Rapid iteration with constant code review.
The Pilot's Correction
Corrective Protocol
// Corrected: Batching Preserved
void Start() {
Renderer r = GetComponent<Renderer>();
MaterialPropertyBlock prop = new MaterialPropertyBlock();
// Set the value on the block, not the material
prop.SetColor("_Color", Random.ColorHSV());
r.SetPropertyBlock(prop);
}
Your Pilot Command
> A skilled Pilot directs the AI to use Property Blocks. You command: "Use a MaterialPropertyBlock to change the color without cloning the material."