A3D_GetReflection

Find the direction something takes after bouncing off a surface, such as a bullet that ricochets.

native bool:A3D_GetReflection(
    Float:directionX,
    Float:directionY,
    Float:directionZ,
    Float:normalX,
    Float:normalY,
    Float:normalZ,
    &Float:x,
    &Float:y,
    &Float:z
);

Parameters

Parameter	Description
Float:directionX	Direction before the bounce on the X axis.
Float:directionY	Direction on the Y axis.
Float:directionZ	Direction on the Z axis.
Float:normalX	Normal of the surface on the X axis.
Float:normalY	Normal on the Y axis.
Float:normalZ	Normal on the Z axis.
&Float:x	Direction after the bounce on the X axis, as long as before.
&Float:y	Direction on the Y axis.
&Float:z	Direction on the Z axis.

Returns

• true when the direction was written.
• false when the normal has no length.

Remarks

The direction mirrors on the surface: the part along the normal turns back and the part along the surface stays. Its length stays too, so a velocity reflects into the velocity after a perfect bounce.

Example

Follows a bullet that ricochets once off the map.

stock bool:GetRicochetEnd(Float:x, Float:y, Float:z, Float:directionX, Float:directionY, Float:directionZ, &Float:endX, &Float:endY, &Float:endZ) {
    new
        Float:hitX,
        Float:hitY,
        Float:hitZ,
        Float:normalX,
        Float:normalY,
        Float:normalZ,
        Float:bounceX,
        Float:bounceY,
        Float:bounceZ
    ;

    if (!A3D_RayCastNormal(x, y, z, x + directionX * 100.0, y + directionY * 100.0, z + directionZ * 100.0, hitX, hitY, hitZ, normalX, normalY, normalZ, .flags = A3D_COLLIDE_MAP)) {
        return false;
    }

    A3D_GetReflection(directionX, directionY, directionZ, normalX, normalY, normalZ, bounceX, bounceY, bounceZ);

    return A3D_RayCast(hitX, hitY, hitZ, hitX + bounceX * 50.0, hitY + bounceY * 50.0, hitZ + bounceZ * 50.0, endX, endY, endZ);
}

Related

• A3D_RayCastNormal: Find the first thing a segment hits, and the direction its surface faces there.
• A3D_GetSurfaceRotation: Find the rotation that stands an object on a surface, such as a crate on a slope.