Shine/Sheen effect on hover for SVG? - css

Question

I'm new to SVG animation and I was hoping someone could help me achieve an effect.
I have two questions actually:
1.) As you can see in this codepen. I have an CSS keyframe animation that draws out a shape, fill a flat color then ends in a SVG gradient. However it doesn't properly transition to that gradient (it just kinda 'pops' to that state at the end)
CSS Animation
#-webkit-keyframes dash {
0% {stroke-dashoffset: 900; fill:#FFF;}
85% {stroke-dashoffset: 0; fill:#FFF;}
90% {fill:#fce669;}
100% {fill:url(#glow);}
}
SVG '#Glow' gradient
<defs>
<linearGradient id = "glow" x1 = "0%" y1 = "0%" x2 = "100%" y2 = "100%">
<stop stop-color = "#fce669" offset = "0%"/>
<stop stop-color = "#fff" offset = "100%"/>
</linearGradient>
</defs>
Is it possible to transition between these states?
Okay that aside, here's my real question:
2.) Ideally, after the drawing animation is complete, I'd like there to be a sheen effect that is also triggered on hover. Like this codepen. I tried animating the color stops on the gradient to achieve this effect and it's pretty terrible.
http://codepen.io/StuffieStephie/pen/eJdWeJ
I really have no idea how to proceed with this. Can someone point me in the right direction?

Answer 1

You seem to came in some hard place here...
I am not sure about the specs recommendations for this, but from tests, it seems that svg's linearGradient can't be animated through CSS. I guess that it's because it is seen as an image, just like CSS gradients are seen as background-image.
Note that Firefox won't even execute the animation if you place a <funcIRI> into it (url(#yourElement)). Once again, I couldn't find the specs about this, so can't tell for sure if that's a bug, but since Chrome is deprecating SMIL, that will probably become an issue quite soon.
But for today, the only workaround I can give you, is to use SMIL.
You can use <animate> elements to animate your linearGradient. In the example above, I do animate only one stop-color of the #glow gradient.
I also used an other animated linear-gradient to the shine effect. This linear-gradient is then applied as the fill attribute of a mask, making the black part of the gradient the only masking of the <mask> element.
Note that chrome only do render offset's animation if you do use absolute values...
svg {
max-width: 100%;
max-height: 100%;
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
margin: auto;
}
.st0 {
stroke-dasharray: 900;
stroke-dashoffset: 0;
fill: url(#glow);
animation: dash 4s linear alternate;
-webkit-animation: dash 4s linear alternate;
}
#keyframes dash {
0% {
stroke-dashoffset: 900;
}
85% {
stroke-dashoffset: 0;
}
}
#-webkit-keyframes dash {
0% {
stroke-dashoffset: 900;
}
85% {
stroke-dashoffset: 0;
}
}
.st2 {
fill: #FFF;
}
<svg version="1.1" id="starmoon" class="icon" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 254.7 220.8" style="enable-background:new 0 0 254.7 220.8;" xml:space="preserve">
<style type="text/css">
.st0 {
stroke: #EFA441;
stroke-miterlimit: 10;
}
</style>
<defs>
<linearGradient id="glow" x1="0%" y1="0%" x2="100%" y2="100%">
<stop stop-color="#FFF" offset="0%">
<animate id="color" attributeName="stop-color" from="#fff" to="#fce669" dur="0.8s" begin="3.2s" fill="freeze" />
</stop>
<stop stop-color="#fff" offset="100%" />
</linearGradient>
<!-- the gradient used by the mask -->
<linearGradient id="shine" x1="0%" y1="0%" x2="100%" y2="100%">
<stop stop-color="white" offset="-10%">
<animate attributeName="offset" values="-.05;.95" dur="2s" begin="color.end" />
</stop>
<stop stop-color="black" offset="-5%">
<animate attributeName="offset" values="0;1" dur="2s" begin="color.end" />
</stop>
<stop stop-color="white" offset="0%">
<animate attributeName="offset" values=".05;1.05" dur="2s" begin="color.end" />
</stop>
</linearGradient>
<mask id="myShiningMask">
<rect x="0" y="0" width="100%" height="100%" fill="url(#shine)" />
</mask>
</defs>
<path fill="url(#glow)" class="st0 icon" d="M169,69.1l5.4-5.4c1.6-1.6,0.8-4.3-1.5-4.7l-42.6-7.6c-0.9-0.2-1.6-0.7-2-1.5l-19.7-38.4c-1-2-3.9-2-5,0
L83.5,49.4c-0.4,0.8-1.2,1.3-2,1.4l-42.7,6.5c-2.2,0.3-3.2,3.1-1.6,4.7L67.3,93c0.6,0.6,0.9,1.5,0.8,2.4l-6.7,42.3
c-0.4,2.2,1.9,3.9,4,3l38.9-18.7c0.8-0.4,1.7-0.4,2.5,0l38.6,19.7c2,1,4.4-0.6,4-2.9l-6.1-42.5c-0.1-0.9,0.2-1.8,0.8-2.4l15.2-15
c10,9.6,16.2,23.1,16.2,38.1c0,29.3-23.7,53-53,53c-10,0-19.3-2.8-27.3-7.6c10.8,21.4,33,36.1,58.6,36.1c36.2,0,65.6-29.4,65.6-65.6
C219.1,102,197.7,76.1,169,69.1z" mask="url(#myShiningMask)" />
<circle class="st2" cx="87.9" cy="67.3" r="12.4" fill="white" />
</svg>