ProjectedBody.cs

public struct ProjectedBody
    {
        public const float DampingDefault = 0.01f;
        public const float TimeStep = 1f / 60f;
        public static readonly float3 Gravity = new float3(0f, -9.81f, 0f);

        public float3 StartPosition;
        public float Damping;
        public float3 Velocity;
        public float3 Position;
        public quaternion Rotation;     
        

        public static ProjectedBody Create(float3 position, Quaternion rotation, float force, float angle, float damping, PhysicsMass mass)
        {
            ProjectedBody body = new ProjectedBody();
            body.Damping = damping;
            body.Position = position;
            body.StartPosition = position;

            rotation = rotation * Quaternion.Euler(angle, 0f, 0f);
            LocalToWorld transform = new LocalToWorld { Value = float4x4.TRS(body.Position, rotation, new float3(1f, 1f, 1f)) };

            PhysicsVelocity velocity = default;
            velocity.ApplyLinearImpulse(mass, transform.Forward * force);
            body.Velocity = velocity.Linear;

            return body;
        }

        public static void ApplyGravityToVelocity(ref float3 velocity, float timeStep, float3 gravity, float gravityFactor = 1f)
        {
            float3 gravityAcceleration = timeStep * gravity;
            velocity += gravityAcceleration * gravityFactor;
        }

        public static void UpdatePositionWithVelocity(ref float3 position, float3 velocity, float timeStep)
        {
            position += velocity * timeStep;
        }

        public void Step(float timeStep = TimeStep)
        {
            ApplyGravityToVelocity(ref Velocity, timeStep, Gravity, 1f);
            Velocity *= math.clamp(1.0f - Damping * timeStep, 0.0f, 1.0f);
            UpdatePositionWithVelocity(ref Position, Velocity, timeStep);
        }

    }