[x3d-public] RenderedTexture support

[Andreas Plesch]

Dear group,

x3dom has a RenderedTexture node which very useful. Prompted by a
x3dom-user list question, I started to think about using
RenderedTextures as faces for a ComposedCubeMapNode which is also
available in x3dom albeit only for ImageTexture sources.

Although I first thought it is technically difficult due to webgl
limitations, after deep diving it turned out that there is a way to
efficiently use gl textures (generated for RenderedTexture) as faces
for gl cube map textures (using gl.copyTexImage2D()).

So I am developing in my cubemap branch of x3dom the ability for
ComposedCubeMapNode to use RenderedTexture which can be updated per
frame, for dynamic mirror effects and probably other uses. Here is an
example:

https://rawgit.com/andreasplesch/x3dom/cubemap/test/regression-suite/test/cases/cubemap/colorcube.html

It more or less works but before I go further I would like to know how
other browser approach dynamic cube maps from a high level. There is
also the x3d GeneratedCubeMapNode which is intended for this effect.
So one question would be which players actually implement a
GeneratedCubeMapNode.

There are quite a few x3d browsers which have a RenderedTexture node.
Do they allow using it with ComposedCubeMap ?

A big question is how recursive mirror in mirror are handled.

Is a RenderedTexture node a target for v.4 ?

Any feedback much welcome,

Andreas

-- 
Andreas Plesch
Waltham, MA 02453