I have created a demo for an svg fill animation. My approach: I'm creating a mask of the original svg and then clipping that mask. Then I animate the clipped version of the mask from bottom to top on hover. My problem is, that while the animation is happening there is a flicker at the base of the svg element. The flicker is at the very base of the svg and is a very thin line. I tried capturing it on a screenshot but it doesn't get picked up.
Does anyone have an idea how I could clean that up?
Demo: https://codepen.io/aki-sol/pen/JjJLxYG?editors=1100
HTML
<svg class="">
<use xlink:href="#heart"></use>
</svg>
<svg viewBox="0 -28 512.00002 512" xmlns="http://www.w3.org/2000/svg">
<path fill="none" d="m471.382812 44.578125c-26.503906-28.746094-62.871093-44.578125-102.410156-44.578125-29.554687 0-56.621094 9.34375-80.449218 27.769531-12.023438 9.300781-22.917969 20.679688-32.523438 33.960938-9.601562-13.277344-20.5-24.660157-32.527344-33.960938-23.824218-18.425781-50.890625-27.769531-80.445312-27.769531-39.539063 0-75.910156 15.832031-102.414063 44.578125-26.1875 28.410156-40.613281 67.222656-40.613281 109.292969 0 43.300781 16.136719 82.9375 50.78125 124.742187 30.992188 37.394531 75.535156 75.355469 127.117188 119.3125 17.613281 15.011719 37.578124 32.027344 58.308593 50.152344 5.476563 4.796875 12.503907 7.4375 19.792969 7.4375 7.285156 0 14.316406-2.640625 19.785156-7.429687 20.730469-18.128907 40.707032-35.152344 58.328125-50.171876 51.574219-43.949218 96.117188-81.90625 127.109375-119.304687 34.644532-41.800781 50.777344-81.4375 50.777344-124.742187 0-42.066407-14.425781-80.878907-40.617188-109.289063zm0 0" />
<mask id="clip2">
<path fill="white" d="m471.382812 44.578125c-26.503906-28.746094-62.871093-44.578125-102.410156-44.578125-29.554687 0-56.621094 9.34375-80.449218 27.769531-12.023438 9.300781-22.917969 20.679688-32.523438 33.960938-9.601562-13.277344-20.5-24.660157-32.527344-33.960938-23.824218-18.425781-50.890625-27.769531-80.445312-27.769531-39.539063 0-75.910156 15.832031-102.414063 44.578125-26.1875 28.410156-40.613281 67.222656-40.613281 109.292969 0 43.300781 16.136719 82.9375 50.78125 124.742187 30.992188 37.394531 75.535156 75.355469 127.117188 119.3125 17.613281 15.011719 37.578124 32.027344 58.308593 50.152344 5.476563 4.796875 12.503907 7.4375 19.792969 7.4375 7.285156 0 14.316406-2.640625 19.785156-7.429687 20.730469-18.128907 40.707032-35.152344 58.328125-50.171876 51.574219-43.949218 96.117188-81.90625 127.109375-119.304687 34.644532-41.800781 50.777344-81.4375 50.777344-124.742187 0-42.066407-14.425781-80.878907-40.617188-109.289063zm0 0" fill="white" />
</mask>
<g mask="url('#clip2')">
<rect width="100%" height="100%" fill="none">
</rect>
</g>
</svg>
CSS:
body {
background: black;
}
rect {
transform: translateY(100%);
fill: yellow;
transition: transform 8s ease-in-out;
will-change: transform;
}
svg:hover rect {
transform: translateY(0);
}
svg path {
stroke: yellow;
}
svg {
width: 300px;
}
.hide {
display: none;
}
You can animate the stroke-dashoffset of a very wide line clipped by the heart. For the stroke you can use again the heart with a use element:
body {
background: black;
}
#line {
stroke-dasharray:465;
stroke-dashoffset:465;
transition: stroke-dashoffset 2s ease-in-out;
}
svg:hover #line {
stroke-dashoffset:0;
}
svg {
width: 300px;
}<svg viewBox="0 0 512 465" xmlns="http://www.w3.org/2000/svg">
<clipPath id="clip">
<path id="heart" fill="none" d="m471.382812 44.578125c-26.503906-28.746094-62.871093-44.578125-102.410156-44.578125-29.554687 0-56.621094 9.34375-80.449218 27.769531-12.023438 9.300781-22.917969 20.679688-32.523438 33.960938-9.601562-13.277344-20.5-24.660157-32.527344-33.960938-23.824218-18.425781-50.890625-27.769531-80.445312-27.769531-39.539063 0-75.910156 15.832031-102.414063 44.578125-26.1875 28.410156-40.613281 67.222656-40.613281 109.292969 0 43.300781 16.136719 82.9375 50.78125 124.742187 30.992188 37.394531 75.535156 75.355469 127.117188 119.3125 17.613281 15.011719 37.578124 32.027344 58.308593 50.152344 5.476563 4.796875 12.503907 7.4375 19.792969 7.4375 7.285156 0 14.316406-2.640625 19.785156-7.429687 20.730469-18.128907 40.707032-35.152344 58.328125-50.171876 51.574219-43.949218 96.117188-81.90625 127.109375-119.304687 34.644532-41.800781 50.777344-81.4375 50.777344-124.742187 0-42.066407-14.425781-80.878907-40.617188-109.289063zm0 0" />
</clipPath>
<path id="line" clip-path="url('#clip')" d="M256,465V0" stroke="gold" stroke-width="512"/>
<use xlink:href="#heart" stroke="gold" ></use>
</svg>