bullet penetration and ricochet mechanics

7/27/2019 Bullet Penetration and Ricochet Mechanics

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Bullet Penetration and Ricochet MechanicsAsset Properties

Certain assets need to have the ability to be denoted by the level designer as "not penetrable." TheFollowing assets will have a "Not Penetrable" property added to them in the Unreal Editor:

Individual BSP faces StaticMeshActor

Material

Bullet Penetration Rules

Every material has two attributes: Damage Reduction and Deviation. Damage Reduction reduces thedamage a bullet does per inch of material it passes through. Deviation determines how much the bulletchanges direction per inch of material it passes through. These effects are determined by the totalthickness of the material.

When a bullet impacts a material, the thickness of the material will be determined. The damage reductionbased on material thickness is applied to the bullet. If the bullet can still do damage, then it will penetratethe material. When the bullet exits the material, the deviation is applied to the bullets direction todetermine its new path. A round will not penetrate any item that is over 15 inches (20 Unreal Units) thickand will not penetrate more than three surfaces regardless of material type and thickness.

Examples with 5.56mm Round: 1 inch Dense Metal door: by default, the round will not penetrate the material. 4 inches of concrete/brick: damage reduced by 120%, does not penetrate, no deviation 2 inch hard wood door: damage reduced by 10%, deviates 10 - 14 degrees. 2 inch Drywall on each side: damage reduced by 4%, deviates 2 - 6 degrees

Ricochet Mechanics

Each individual bullet has 15% chance to ricochet off dense metal, mud brick, stone/ceramic tile, andconcrete/brick. The base ricochet angle is the opposite angle of impact. The final ricochet angle is arandom angle anywhere within that angle of impact in both Y and Z dimensions. This allows a bullet toricochet up or down from its original path. A bullet will only ricochet if it hits a surface within 15 degrees ofthe material plane, and it can only ricochet off a maximum of three surfaces.

Penetration Tables by Round Type5.56mm Round

Material (per inch) Damage Reduction DeviationFlesh/Organic 12.5% 1 - 3Concrete/Brick 30% 8 - 10Fabric/Cloth 2% 0 - 2Metal, Dense N/A N/A

Metal, Thin 7% 6 - 10Mud Brick 25% 1 - 3Paper/Cardboard 3% 0 - 1

Plastic 3% 2 - 3Rubber 2% 2 - 4Wood, Natural 5% 4 - 8Wood, Hard/Processed 5% 5 - 7Tile, Stone/Ceramic 30% 9 - 11Plaster/Drywall 2% 1 - 3Glass 0% 1 - 2Sand 17% 0 - 15.56mm Match Ammo

Material (per inch) Damage Reduction Deviation


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Flesh/Organic 12.5% 0 - 2Concrete/Brick 30% 5 - 7Fabric/Cloth 2% 0 - 2Metal, Dense N/A N/A

Metal, Thin 7% 3 - 7Mud Brick 25% 0 - 1Paper/Cardboard 3% 0Plastic 3% 0 - 2Rubber 2% 1 - 2Wood, Natural 5% 2 - 4Wood, Hard/Processed 5% 3 - 5Tile, Stone/Ceramic 30% 7 - 9Plaster/Drywall 2% 0 - 2Glass 0% 0 - 1Sand 17% 0Mossberg Shotgun (Breaching)


Flesh/Organic 50% N/AConcrete/Brick N/A N/AFabric/Cloth 30% 1 - 4

Metal, Dense N/A N/A

Metal, Thin N/A N/AMud Brick N/A N/APaper/Cardboard 10% 1 - 3

Plastic 20% 3 - 9

Rubber 25% 2 - 8

Wood, Natural 20% 2 - 8

Wood, Hard/Processed 20% 2 - 8

Tile, Stone/Ceramic N/A N/APlaster/Drywall 40% 2 - 6Glass 10% 0 - 3Sand N/A N/AMossberg Shotgun (Combat)


Flesh/Organic 10% 5 - 10

Concrete/Brick N/A N/A

Fabric/Cloth 2% 0 - 1


Metal, Thin 15% 6 - 10

Mud Brick 50% 4 - 8

Paper/Cardboard 2% 0 - 1

Plastic 7% 1 - 3

Rubber 5% 1 - 3

Wood, Natural 15% 2 - 6Wood, Hard/Processed 15% 2 - 6Tile, Stone/Ceramic N/A N/A

Plaster/Drywall 5% 1 - 4Glass 3% 0 - 2Sand N/A N/A


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M9 Pistol (9mm rounds)


Flesh/Organic 15% 3 - 6

Concrete/Brick N/A N/A

Fabric/Cloth 25% 1 - 3


Metal, Thin 35% 4 - 9Mud Brick N/A N/A

Paper/Cardboard 10% 0 - 4

Plastic 10% 1 - 2

Rubber 8% 1 -2

Wood, Natural 25% 1 - 4

Wood, Hard/Processed 25% 1 - 4

Tile, Stone/Ceramic N/A N/A

Plaster/Drywall 4% 0 - 2Glass 2% 0 - 1Sand 60% 1 - 2

bullet penetration and ricochet mechanics

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