If RenderMan RIB output was added, Arbaro trees could
be rendered straight with 3Delight, AIR, Aqsis, Pixie,
Pixar's PhotoRealistic RenderMan or RenderDotC. That is
support for six (!) renderes by adding just one new format.
And if you output bicubics, the required resolution
would be very light compared to polygons. Plus you
don't need to output normals or uv coordinates as they
are implicitly generated by the renderer at rendertime.
Last but not least, all details can be added through
shaders at rendertime -- e.g ultra detailed bork
through a procedural displacement shader.