Aim helper in realistic sniper game

Questions & Answers
1

I’m making a sniper game with gravity and wind influence on bullet. I’m moving bullet with constant velocity in forward direction and adding physics.gravityTime.FixedDeltatime.
So if there is a target 300 units away my bullet with take 36 frames to reach it(300/velocityTime.FixedDeltatime) which we will call predictedFrames, when i multiply predictedFrames with gravity it should give mei the y position of bullet after 36 frames but it gives me the wrong position.
I did Debug.Log(physics.gravity*Time.FixedDeltatime) and it give me -0.2 which should be the gravity per frame but it’s not, after the first frame bullet y position is 0.0011 something.
I did everything but nothing worked.
plz help

2

Hi @notijaz you’re really close but remember that acceleration is a change in velocity, i.e. a change in distance over time, over time. predictedFrames * Time.fixedDeltaTime represents the amount of total travel time your bullet has before it reaches the target at 300 units. The equation to calculate fall distance under acceleration is:

y_fall = 0.5 * acceleration * time * time;     //this is the time over time portion for distance travelled

Check this out: Equations for a falling body - Wikipedia

And here’s some (updated) code that should work for you:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BulletController : MonoBehaviour
{
    float initial_velocity = 417f;
    float distance_to_target = 300f;
    float time_to_target;
    int predictedFrames;
    float bullet_drop;
    Vector3 bulletvelocity;

    // Start is called before the first frame update
    void Start()
    {
        bulletvelocity = initial_velocity * (transform.rotation * new Vector3(1, 0, 0)); // +x velocity
        Debug.Log(bulletvelocity);

        time_to_target = distance_to_target / initial_velocity;
        Debug.Log("Time to reach target: " + time_to_target);

        predictedFrames = (int) ((distance_to_target / initial_velocity) / Time.fixedDeltaTime);
        Debug.Log("Frames to reach target: " + predictedFrames);

        bullet_drop = -Physics.gravity.y * 0.5f * time_to_target * time_to_target;
        Debug.Log("Distance to drop: " + bullet_drop);

        bullet_drop = -Physics.gravity.y * 0.5f * predictedFrames * Time.fixedDeltaTime * predictedFrames * Time.fixedDeltaTime;
        Debug.Log("Distance to drop: " + bullet_drop);

        Debug.Log(Physics.gravity);

    }

    // Update is called once per frame
    void FixedUpdate()
    {
        bulletvelocity += Physics.gravity * Time.fixedDeltaTime;
        transform.position += bulletvelocity * Time.fixedDeltaTime;
    }
}