Agripa's Pantheon

Hi, since I first read about portals coming to cycles I’ve been fooling around with them.
I thought of a proper test scene, several nice examples came to my mind, foremost were Tadao Ando’s water chappel and Agripa’s Pantheon. This last one, along with Hagia Sophia are the two that topped my “10 places to visit before I die”, since I had the chance to visit Hagia Sophia a couple years back (and fall in love with it) I thought that it would be cool to try to learn something and “visit” the Pantheon in the meantime.
Not only wanted to test portals, but some other things in the way, the texture is a full procedural, cracks and all, and it was quite fun play with it. The dust, to add to the imperfections, and finally the “cardinal” that adds color to the scene, and also lets me play with some other fun concepts like hair and particle instances.
Meanwhile I’ve found a couple fun things. Portals, HDRIs and Volumetrics are a strange combination, since portals concentrate enviroment rays on it, the volumetrics ramp up when suddenly tons of light come thru it. It’s a little hard to fine tune, I wanted to be less subtle the “god ray” effect, but this is the best I could come with.
Everything modeled and textured from scratch in under 6 hours total, well all materials are procedural besides the fur color which I hand painted in blender. I’ve abused the “pointiness” node, which is cool. And even the bird legs are a skin modifier with 2 simple displace nodes with procedural textures and more “pointiness” based material.
The clouds and the signature are added in compositor, along some minor color correction and lens distortion.
Blender 2.74.5 1500 samples 4hr @GTX 780
Hope you like, but just the same any comments and criticism will be more than welcome.

Well, now this is a new test. Rendered on 2.75 testbuild using portals, this time I just left the pantheon and the cardinal, no volumetrics nor dust particles. Cleaned nicely with 1000 samples in about 2hr. The rest is compositor and node magic, shorter render, and at least to my eyes, nicer overall efect, even if fake.

Very nice example of light portal use.
I like the first version much better.
The blue atmosphere interacts nicely and in a very subtle way with the yellow touch of light, and the bird is perfectly detached with that bright red.
All this being kind of taken away in the second render, with white walls and the much too bright sun on it, even though it brings out the wall texture.
Well, very nice work, congrats!