I am not a Spine animator, so I am unsure of the actual cause.
However, I did buy Spine Pro to try and fix any issues if its an export setting or otherwise.
view from editor:
Editor Preview: VIDEO
Web Preview: VIDEO
Player Code:
animationPlayer = new spine.SpinePlayer("animation", {
jsonUrl: "test/skeleton.json",
atlasUrl: "test/Moon.atlas",
showControls: false,
alpha: true,
backgroundColor: "#00000000",
animation: "Idle",
defaultMix: 0,
loop: false,
viewport: {
width: 300,
height: 500
}
});
CSS:
element.style {
display: block;
width: 100%;
height: 100%;
}
canvas[Attributes Style] {
aspect-ratio: auto 500 / 250;
}
canvas {
overflow-clip-margin: content-box;
overflow: clip;
}