How to create followspot effect using HTML CSS and jQuery ?

Last Updated : 06 Jul, 2023

The follow-spot effect (spotlight effect) is an effect that can be easily implemented using jQuery. The effect is quite popular for the opening or front banner design for any website.

Approach: The approach is to use circle CSS on the mouse movement effect using the mousemove() function provided by jQuery.

HTML Code: The HTML code is used to design the basic structure of the body. In this section, we will use a <div> tag that wrapped inside a <section> tag.

html

<!DOCTYPE html>
<html lang="en">
 
<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, 
                                   initial-scale=1.0" />
    <title>Split Effect</title>
</head>
 
<body>
    <section>
        <div class="geeks"></div>
    </section>
</body>
 
</html>

CSS Code: The CSS property is used to set the style to the image.

CSS

body {
    margin: 0;
    padding: 0;
}
 
section {
    background: url(geeks.png);
    position: relative;
    width: 100%;
    height: 100vh;
    background-size: cover;
}
 
.geeks {
    position: absolute;
    width: 100%;
    height: 100%;
}

jQuery Code: We have used the mousemove() function to track the mouse movement and apply the effect according to cursor movement. For creating a circle, just use radial-gradient along with the X and Y points that are basically the location of the cursor and provide a radius of 30% for roundness. Don’t forget to apply this CSS to the div tag.

javascript

$(document).mousemove(function (e) {
    let X = e.pageX;
    let Y = e.pageY;
    $(".geeks").css("background",
        "radial-gradient(circle at "
        + X + "px " + Y +
        "px, transparent, #000 30%)"
    );
});

Complete Code: In his section, we will combine the above three sections of code (HTML, CSS, and jQuery) to create a follow-spot effect.

html

<!DOCTYPE html>
<html lang="en">
 
<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, 
                                   initial-scale=1.0" />
 
    <title>Split Effect</title>
 
    <script src=
"https://code.jquery.com/jquery-3.4.1.js">
    </script>
 
    <style>
        body {
            margin: 0;
            padding: 0;
        }
 
        section {
            background: url(
"https://media.geeksforgeeks.org/wp-content/cdn-uploads/Geek_logi_-low_res.png");
            position: relative;
            width: 100%;
            height: 100vh;
            background-size: cover;
        }
 
        .geeks {
            position: absolute;
            width: 100%;
            height: 100%;
        }
    </style>
</head>
 
<body>
    <section>
        <div class="geeks"></div>
    </section>
 
    <script>
        $(document).mousemove(function (e) {
            let X = e.pageX;
            let Y = e.pageY;
            $(".geeks").css(
                "background",
                "radial-gradient(circle at " +
                X +
                "px " +
                Y +
                "px, transparent, #000 30%)"
            );
        });
    </script>
</body>
 
</html>