Messages

1

General / Re: Unwanted Motion Blur

« on: March 03, 2024, 09:55:08 pm »

Thanks man! 

I didn’t know what Monitor Ghosting was    and you really helped me!

2

General / Unwanted Motion Blur

« on: March 02, 2024, 05:39:42 pm »

Hi! (and thank u for reading this  )

Now that I've implemented interpolation and I have a very smooth movement, I encountered a problem while moving my rectangle.
If I move it slowly, it goes perfectly; but when I move it fast, there's like a motion blur effect that makes it strange.
I'm using Windows 10 with an Nvidia GPU (GeForce RTX 2060) and my program uses SFML 2.6.1.

Minimal Example of code:

#include <SFML/Graphics.hpp>
#include <Kairos/Timestep.hpp>

sf::Vector2f lerpV(sf::Vector2f a, sf::Vector2f b, float t)
{
    return a * (1 - t) + b * t;
}

void Update(sf::Shape* s, float dt, sf::Vector2f* vel, sf::Vector2f* pos)
{
    float mass = 1.f;
    float f = 100.f;
    sf::Vector2f force = sf::Vector2f(0.f, 0.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W))
        force += sf::Vector2f(0.f, -f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A))
        force += sf::Vector2f(-f, 0.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S))
        force += sf::Vector2f(0.f, f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D))
        force += sf::Vector2f(f, 0.f);

    // Inertia:
    force += sf::Vector2f(-vel->x * 1.f * mass * 9.81f, -vel->y * 1.f * mass * 9.81f);

    float acceleration_x = force.x / mass;
    float acceleration_y = force.y / mass;
    *vel += sf::Vector2f(acceleration_x * dt, acceleration_y * dt);
    *pos += *vel;
}

int main()
{
    sf::RenderWindow window(sf::VideoMode(1200, 800), "Motion Blur Problem");
    window.setVerticalSyncEnabled(false);
    window.setFramerateLimit(144);

    sf::RectangleShape shape(sf::Vector2f(200.f, 200.f));
    shape.setFillColor(sf::Color::Green);
    sf::Vector2f velocity = sf::Vector2f(0.f, 0.f);

    sf::Vector2f pre = shape.getPosition();
    sf::Vector2f position = shape.getPosition();

    kairos::Timestep timestep;
    timestep.setStep(1.f / 60.f);
    timestep.setMaxAccumulation(0.25f);
    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        timestep.addFrame();
        while (timestep.isUpdateRequired())
        {
            pre = position;
            float dt = timestep.getStepAsFloat();

            Update(&shape, dt, &velocity, &position);
        }
        float interpolation = timestep.getInterpolationAlphaAsFloat();

        window.clear();
       
        shape.setPosition(lerpV(pre, position, interpolation));
        window.draw(shape);

        window.display();
    }

    return 0;
}

My main questions are:
1. is this an optical illusion made by its movement? (so I should only move it slowly)
2. is this a problem of my monitor or my eyes? (so I should cry)
3. or is this a bug? and if yes, how can I fix it?

3

General / Re: Casual Stuttering Problem

« on: February 27, 2024, 05:27:16 pm »

Thanks man, you saved me!

4

General / Casual Stuttering Problem

« on: February 27, 2024, 07:49:15 am »

Hi,
(and thank you for reading this)

I'm having an issue where: when I run my application and I move my object, sometimes it runs perfectly and with smooth movements, and other times it stutters a lot.
I'm using Windows 10 with an Nvidia GPU (GeForce RTX 2060) and my program uses SFML 2.6.1.


(sorry but I don't know how to put the code in the "white scrollable box")
Minimal Example:

#include <SFML/Graphics.hpp>
//#include <iostream>

void Update(sf::CircleShape* s, float dt, sf::Vector2f* vel)
{
    float mass = 1.f;
    sf::Vector2f force = sf::Vector2f(0.f, 0.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W))
        force += sf::Vector2f(0.f, -100.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A))
        force += sf::Vector2f(-100.f, 0.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S))
        force += sf::Vector2f(0.f, 100.f);
    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D))
        force += sf::Vector2f(100.f, 0.f);

    // Inerzia:
    force += sf::Vector2f(-vel->x * 1.f * mass * 9.81f, -vel->y * 1.f * mass * 9.81f);

    float acceleration_x = force.x / mass;
    float acceleration_y = force.y / mass;
    *vel += sf::Vector2f(acceleration_x * dt, acceleration_y * dt);
    s->move(*vel);
}

int main()
{
    const float dt = 1.f / 60.f;

    sf::RenderWindow window(sf::VideoMode(1200, 800), "Stutter Problem");
    window.setVerticalSyncEnabled(false);
    window.setFramerateLimit(144);
    sf::Clock clock;

    sf::CircleShape shape(100.f);
    shape.setFillColor(sf::Color::Green);
    sf::Vector2f velocity = sf::Vector2f(0.f, 0.f);

    float newTime = 0.f, frameTime = 0.f;
    float currentTime = clock.getElapsedTime().asSeconds();
    float accumulator = 0.f;
    while (window.isOpen())
    {
        newTime = clock.getElapsedTime().asSeconds();
        frameTime = newTime - currentTime;
        if (frameTime > 0.25f)
            frameTime = 0.25f;
        currentTime = newTime;
        accumulator += frameTime;

        // Handle Inputs:
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        while (accumulator >= dt)
        {
            Update(&shape, dt, &velocity);
            accumulator -= dt;
        }

        window.clear();
        window.draw(shape);
        window.display();
        sf::sleep(sf::milliseconds(1));
    }

    return 0;
}

and attached here I put a video with the type of stutter that I encounter often.