Author Topic: Physical light simulation  (Read 4693 times)

2014-01-29, 01:01:20

Marciortiz

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Hi all,

I am not sure if I'm asking the question correctly, but how can we simulate an actual 3D physical light inside Corona?

I have attached some samples to explain a bit of what I am trying to achieve.

Corona has a very good way to deal with lights that I am trying to in fact create a light source that actually bounces and produce those rays of light that we got on real life, instead of using planes/spheres etc.

I saw a very good examples on past from Fryrender (Arion today) and I am just wondering if I can get some instructions for that?

Cheers for now :)

2014-01-29, 11:13:48
Reply #1

maru

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You probably mean caustics. :)
It does work by default in Corona but to make it render faster, just place a glass object in your scene, add a light and switch renderer from "progressive" to bidir or vcm.

2014-01-29, 14:39:28
Reply #2

Marciortiz

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Hi Maru, thanks for your reply.

So, if I for instance got a light bulb model and my inside fillet has emission material, would that work instantly?

Doesn't seem to work like that to be honest, as I did that test even with other shapes but didn't work.

I don't really mind about render time at this stage, I just want to get the most closed to light simulation Corona can deliver. :)

2014-01-29, 15:16:58
Reply #3

Marciortiz

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I just did a test with a light sphere also. didn't work either.

Not sure what to do :(

2014-01-29, 16:18:22
Reply #4

romullus

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Did you switch renderer from progressive to bidir/vcm?
I'm not Corona Team member! Everything i say, is my personal opinion only. Render Legion does not endorse my words nor actions.

2014-01-29, 17:41:49
Reply #5

Marciortiz

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I did, and did not create anything different.

In fact, I am testing while I'm writing, and the only difference I can notice is that I got already I high number of passes and the image is very noisy.


2014-01-29, 17:58:18
Reply #6

maru

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I don't get it. Please provide us with screenshots of what you are doing and what you are trying to achieve.

2014-01-29, 18:10:56
Reply #7

Marciortiz

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Alright.

What I am trying to achieve is pretty much the light effect of what you got from my first post (obviously I wont get the same as I don't have the same geometry, light etc but I don't even get the caustics usual behavior).

If you see the attached image, you will notice that I got a chandelier on top, which has sphere light (and some objects with Emission), but I got nothing even close to caustics. Those lamp shades I won't expect much from them, but I am still believing that the sphere Light inside the lampshade should for some reason react differently with the glass bellow. I am not an expert on that, I'm learning Corona but for me doesn't look right. Those two images are done on progressive render and I don't think is worth to post any bidir/vcm as they came out VERY noisy therefore I haven't save it. (I'm taking a night shot as we speak, on progressive again).

Cheers.

2014-01-29, 19:04:47
Reply #8

romullus

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I might be wrong, but these glass things under lamp shades doesn't look like they have thickness. One must have correct geometry, materials and render settings in order to get caustics. And if you want caustics in progressive mode, make sure MSI is set to 0.
I'm not Corona Team member! Everything i say, is my personal opinion only. Render Legion does not endorse my words nor actions.

2014-01-29, 22:10:40
Reply #9

Marciortiz

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Thanks Romulus, in fact the geometry was a simple polygon. Just changed here to see if works.

Night scene, I might get back tomorrow evening with some results (I hope).

2014-01-31, 21:48:24
Reply #10

Marciortiz

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Alright, didn't work as I was expecting.

What is the difference between progressive and bidir/vmc? I cannot achieve even near the quality of progressive once I switch to bidir, something must be wrong...

I would appreciate any sort of help.

Thanks,

2014-01-31, 22:08:44
Reply #11

romullus

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Bidir/vcm has some limitations, but it's certainly doable: http://corona-renderer.com/forum/index.php/topic,2450.msg17900.html#msg17900
I'm not Corona Team member! Everything i say, is my personal opinion only. Render Legion does not endorse my words nor actions.

2014-01-31, 22:16:37
Reply #12

Marciortiz

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Romullus, thanks for been so helpful :)

That sounds like the instruction I am after :)

I will open my max and render now, possibly post tomorrow.

Massive appreciate it!

2014-02-01, 11:39:16
Reply #13

Marciortiz

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Morning all,

Here is the render.

I can't let it go more than the time I already done, won't be achievable to do commercially.

If Bidir/VCM is faster, I have no doubt that I am doing something wrong.