Hey,
I want to build a sprite sheet generator tool were users can drag n drop multiple images from their computer into the WebGL window then export/download a sprite sheet.
I did some searching and it seams it was once achieved, but the files are no longer available.
Does anybody know if there is a method for doing this?
As a minimum I’d just need the file paths from dragged files.
Seems I have found something to suffice for now, but would prefer the Drag n Drop to eliminate and possible native file browser issues.
https://github.com/greggman/getuserimage-unity-webgl
+1 - it would great to let user drag n’ drop media - sound, video, images, etc…
It’s not really realistic to pipe-in images into the WebGL runtime, due to memory and texture representation issues. A 4k square image will crash your game trying to process it.
where Unity Web Player app is running?on frontend or backend?
Thanks, that was a good starting point for me. Unfortunately the custom WebGL Template used in the repository is outdated with newer Unity versions.
To add Drag & Drop in Unity 2021 follow the docs on how to create custom WebGL Templates: Copy the Default template from C:\Program Files\Unity\Hub\Editor<version>\Editor\Data\PlaybackEngines\WebGLSupport\BuildTools\WebGLTemplates and place it inside the Assets\WebGLTemplates directory in your project.
Then you’ll have to add this code to index.html that sends the drop event to a script in Unity via SendMessage when the Unity game instance is created inside the scripts onload function:
container.addEventListener('dragover', (event) => {
event.preventDefault();
});
container.addEventListener('drop', (event) => {
event.preventDefault();
const files = event.dataTransfer.files;
const first = files[0];
unityInstance.SendMessage("FileReceiver", "FileSelected", window.URL.createObjectURL(first), first);
});
The complete file looks like this:
Drag & Drop - index.html
<!DOCTYPE html>
<html lang="en-us">
<head>
<meta charset="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Unity WebGL Player | {{{ PRODUCT_NAME }}}</title>
<link rel="shortcut icon" href="TemplateData/favicon.ico">
<link rel="stylesheet" href="TemplateData/style.css">
</head>
<body>
<div id="unity-container" class="unity-desktop">
<canvas id="unity-canvas" width={{{ WIDTH }}} height={{{ HEIGHT }}}></canvas>
<div id="unity-loading-bar">
<div id="unity-logo"></div>
<div id="unity-progress-bar-empty">
<div id="unity-progress-bar-full"></div>
</div>
</div>
<div id="unity-warning"> </div>
<div id="unity-footer">
<div id="unity-webgl-logo"></div>
<div id="unity-fullscreen-button"></div>
<div id="unity-build-title">{{{ PRODUCT_NAME }}}</div>
</div>
</div>
<script>
var container = document.querySelector("#unity-container");
var canvas = document.querySelector("#unity-canvas");
var loadingBar = document.querySelector("#unity-loading-bar");
var progressBarFull = document.querySelector("#unity-progress-bar-full");
var fullscreenButton = document.querySelector("#unity-fullscreen-button");
var warningBanner = document.querySelector("#unity-warning");
// Shows a temporary message banner/ribbon for a few seconds, or
// a permanent error message on top of the canvas if type=='error'.
// If type=='warning', a yellow highlight color is used.
// Modify or remove this function to customize the visually presented
// way that non-critical warnings and error messages are presented to the
// user.
function unityShowBanner(msg, type) {
function updateBannerVisibility() {
warningBanner.style.display = warningBanner.children.length ? 'block' : 'none';
}
var div = document.createElement('div');
div.innerHTML = msg;
warningBanner.appendChild(div);
if (type == 'error') div.style = 'background: red; padding: 10px;';
else {
if (type == 'warning') div.style = 'background: yellow; padding: 10px;';
setTimeout(function() {
warningBanner.removeChild(div);
updateBannerVisibility();
}, 5000);
}
updateBannerVisibility();
}
var buildUrl = "Build";
var loaderUrl = buildUrl + "/{{{ LOADER_FILENAME }}}";
var config = {
dataUrl: buildUrl + "/{{{ DATA_FILENAME }}}",
frameworkUrl: buildUrl + "/{{{ FRAMEWORK_FILENAME }}}",
#if USE_WASM
codeUrl: buildUrl + "/{{{ CODE_FILENAME }}}",
#endif
#if MEMORY_FILENAME
memoryUrl: buildUrl + "/{{{ MEMORY_FILENAME }}}",
#endif
#if SYMBOLS_FILENAME
symbolsUrl: buildUrl + "/{{{ SYMBOLS_FILENAME }}}",
#endif
streamingAssetsUrl: "StreamingAssets",
companyName: {{{ JSON.stringify(COMPANY_NAME) }}},
productName: {{{ JSON.stringify(PRODUCT_NAME) }}},
productVersion: {{{ JSON.stringify(PRODUCT_VERSION) }}},
showBanner: unityShowBanner,
};
// By default Unity keeps WebGL canvas render target size matched with
// the DOM size of the canvas element (scaled by window.devicePixelRatio)
// Set this to false if you want to decouple this synchronization from
// happening inside the engine, and you would instead like to size up
// the canvas DOM size and WebGL render target sizes yourself.
// config.matchWebGLToCanvasSize = false;
if (/iPhone|iPad|iPod|Android/i.test(navigator.userAgent)) {
// Mobile device style: fill the whole browser client area with the game canvas:
var meta = document.createElement('meta');
meta.name = 'viewport';
meta.content = 'width=device-width, height=device-height, initial-scale=1.0, user-scalable=no, shrink-to-fit=yes';
document.getElementsByTagName('head')[0].appendChild(meta);
container.className = "unity-mobile";
// To lower canvas resolution on mobile devices to gain some
// performance, uncomment the following line:
// config.devicePixelRatio = 1;
canvas.style.width = window.innerWidth + 'px';
canvas.style.height = window.innerHeight + 'px';
unityShowBanner('WebGL builds are not supported on mobile devices.');
} else {
// Desktop style: Render the game canvas in a window that can be maximized to fullscreen:
canvas.style.width = "{{{ WIDTH }}}px";
canvas.style.height = "{{{ HEIGHT }}}px";
}
#if BACKGROUND_FILENAME
canvas.style.background = "url('" + buildUrl + "/{{{ BACKGROUND_FILENAME.replace(/'/g, '%27') }}}') center / cover";
#endif
loadingBar.style.display = "block";
var script = document.createElement("script");
script.src = loaderUrl;
script.onload = () => {
createUnityInstance(canvas, config, (progress) => {
progressBarFull.style.width = 100 * progress + "%";
}).then((unityInstance) => {
loadingBar.style.display = "none";
fullscreenButton.onclick = () => {
unityInstance.SetFullscreen(1);
};
container.addEventListener('dragover', (event) => {
event.preventDefault();
});
container.addEventListener('drop', (event) => {
event.preventDefault();
const files = event.dataTransfer.files;
const first = files[0];
unityInstance.SendMessage("FileReceiver", "FileSelected", window.URL.createObjectURL(first), first);
});
}).catch((message) => {
alert(message);
});
};
document.body.appendChild(script);
</script>
</body>
</html>
This was the first hit on Google so I thought I’d share.