In previewing your hype document, I believe I'm able to see the scene just fine in Safari for the mac. If there's something specific to your setup that'd be good to know. Perhaps if it is published you can send a link to that version that reproduces the problem.
I'm guessing though you might be embedding the animation in another page? If so one thing to look out for when using Flexible Layout with a 100% height is that your containing div not have a height specified. This is a common problem, and in this case the browser would think the height is 0px, and thus 100% of 0px is 0px.
The easiest way to check this out would be to use the browser's web inspector's DOM "Elements" navigator and see what it thinks the height of the hype div actually is.
The basic solutions are:
- Uncheck the height scale in the scene/layout editor so it does not use flexible layout on height
- Introduce a container that has a height specified
- Use a script that tries to be pretty intelligent about preserving a height to width ratio, like this one by @h_classen:
Creating a Flexible Tumult Hype Document within a DIV with no set 'height'
But I think we'd need to verify this is the problem you are hitting to know that it is the right solution.