[x3d-public] rendering the X3D standard...is it extensive enough

[Michalis Kamburelis]

2017-10-18 17:53 GMT+02:00 John Carlson <yottzumm at gmail.com>:
> I am wondering if the X3D standard is complete or extensive enough to
> provide for pixel perfect equality between browsers.   This is important for
> archiving.   Has this been a goal?
>

I don't think pixel-perfect equality between X3D browsers is, or even
should be, the goal of X3D. I don't think it's even possible, if we
allow a wide range of implementation methods.

OpenGL[ES] / WebGL / Direct3D do not guarantee pixel-perfect equality,
you may have differences even between GPUs of the same vendor, due to
internal optimizations. In general, all rendering algorithms, on GPU
or not, will likely have optimizations that make it impossible to
guarantee pixel-perfect equality between each other. And then, there
are thousands of optimizations that every browser does for rendering
(like using imprecise floats, both on CPU and in shader on GPU), and
every browser does it a little differently.

Regards,
Michalis