gravitational lensing

[AEBI_VINCENT]

I realise that this is more of a hypothetical topic, but could it be possible to achieve gravitational lensing with Vray? I can't think of a single instance where this effect would come of use, other than visualizing astrophysical situations like black holes.

I suppose the Vray light rays aren't affected by any form of gravitational modifier in 3ds max? The goal would be to place a massive enough object in front of the camera to bend the light rays around it so anything behind the object would become visible, although distorted.

[^Lele^]

We surely do not simulate the bending of spacetime by gravity.
Rays are cast straight, in a vacuum which is topologically flat.

The one way to *fake* the effect *could* be with a fully transparent, but physical lens (i.e. a sphere).
IoR can be mapped so to fade to 1.0 at the edges.

Fair warning: a black hole contains a singularity, even general relativity (or spacetime.) breaks there.
It's also likely we don't have the representability for the values with which to map the IoR,even when at the event horizon, well away from a singularity.
Meaning you won't be able to pull stuff from behind the spherical area to the front, no matter how hard you'll try, as we'd likely run out of available FP precision first.

On the plus side, no one will be able to tell you it's looking wrong. ^^

[fixeighted]

Oh no, not another society full of absolute nutters...the Flatvacuumers!

[roysgi]

You might add dark matter

[AEBI_VINCENT]

We surely do not simulate the bending of spacetime by gravity.
Rays are cast straight, in a vacuum which is topologically flat.

The one way to *fake* the effect *could* be with a fully transparent, but physical lens (i.e. a sphere).
IoR can be mapped so to fade to 1.0 at the edges.

Fair warning: a black hole contains a singularity, even general relativity (or spacetime.) breaks there.
It's also likely we don't have the representability for the values with which to map the IoR,even when at the event horizon, well away from a singularity.
Meaning you won't be able to pull stuff from behind the spherical area to the front, no matter how hard you'll try, as we'd likely run out of available FP precision first.

On the plus side, no one will be able to tell you it's looking wrong. ^^

Right, anything at or beyond the event horizon would be entirely speculative. You could basically feed random math to Vray and the end user couldn't tell if the result is actually right or wrong, as long as it looked like reality or what we perceive as reality.
I never thought about mapping the IOR slot, will try some stuff to see the results.

So yesterday after I opened this thread I kept researching and I found this paper some guy named Eric Bruneton wrote, it goes by the title "Real-time High-Quality Rendering of Non-Rotating Black Holes". It looks like he has done the actual math and he came up with a solution that you can watch in your browser. Of yourse these calculations (which are way too complex for me to understand, they look like foreign shapes to me) may not apply to Vray, it's just another interesting approach on this fascinating topic.

You can find the paper here:
https://arxiv.org/pdf/2010.08735.pdf

The resulting demo of his findings here:
https://ebruneton.github.io/black_ho...=35874&cp=9110

And his website, if anyone cares:
http://www-evasion.imag.fr/Membres/Eric.Bruneton/


have a great day!

[^Lele^]

Thanks for the links!
Super interesting job, they did!

another interesting approach on this fascinating topic.

Do tell!
I'm a huge fan of Physics, and who doesn't like black holes? ^^

[fixeighted]

Awesome demo on his page!
I knew there was a reason I just spent 1200 quid on a shiny hdr monitor and this is definitiely it

Looks very similar to the Interstellar approach...or was it part of that research you think? Very cool anyway and thanks for posting it.

[Buck]

We surely do not simulate the bending of spacetime by gravity.
Rays are cast straight, in a vacuum which is topologically flat.

Typical.

[^Lele^]

Typical.

We shall try and do better in the future, although there is a chance we already had. (blatant self-promotion.) ^^

[fixeighted]

LOL that is very funny...although I had already read it next year.

[AEBI_VINCENT]

Quantum foaming at the mouth got me good, I almost feel awake now^^

Looks very similar to the Interstellar approach...or was it part of that research you think? Very cool anyway and thanks for posting it.

Definitely, big fan myself. I think the interstellar-approach ist the easiest understandable depiction at this time, so people recreate it.