Water Caustics

[JuanGG]

Re: Water Caustics

hey Dalomar, can you send me that scene too, please?

j.gt@live.com

[pacha]

Re: Water Caustics

Hi all,

Actually, I'm facing a very similar problem. Can you please post the detailed render settings or the visopt file??

[thomthom]

Re: Water Caustics

Hi everyone. I've been trying to make a swimming pool with water caustics and i can't get it. That's what i would like to do:



I've made millions of trials and everything i can do is thing like this:



I like this water, but i can't get caustics. I make a surface, aply bump map on it, check caustics on like tha manual says... but it doesn't work .I hope you could help me.

So, my questions are:

- has the water need to be modeled in sketchup (sandbox) or it can be a flat surface with bump (or noise) aplied?

- it has to be a light pointing to the water or we can get caustics effect only with sketchup sun (physical camera enabled)? what light is the best for that (rectangular, omni, sun...?

- Has the physical camera need to be enabled or we can get caustics effect only with skydome?

- Have the swimming pool tiles to be reflective?

Many thanks to everyone

Where did you get hold of that dried mud texture? I was looking for such a texture some months ago for a project I did.

[pacha]

Re: Water Caustics

Hi Dalomar,

Can you send me the SU model please??

anas.zn@gmail.com

Regards,

[dalomar_cg]

Re: Water Caustics

I've got to track it down...I'm not 100% sure where it has ended up.

[40th]

Re: Water Caustics

This is as far as I got without messing with things too much

So how can i produce water caustics on the bottom of the pool like yours?
I've tried but unsuccessfully. The water mtl has displacement map, transparency, and refraction.
I checked the caustic refl. and refraction.

[Ibontxu]

Re: Water Caustics

I think there had been a confussion here. I didn't receive a mail from Dalomar (now i iknow that he sent me and the problem had been with my hotmail, i don't know why but i hadn't received that mail). I thought he was busy so i didn't insist. Few time later i stopped using vray and tried with other render engines, so i went from asgvis forum for some time, vray had so much faults that i thought i will never use it again.

But with the new release i started to use it again (although it has the big problem of its huge starting times) but i didn't remember of this post.

I want to apologize to everyone not for answering. I tried thousand of times but i never was able to get caustics. Thomthom, I think that texture is from CGtextures, but i don't remember very well. If you want i can send you.

[40th]

Re: Water Caustics

Damien,
Can you explain how to get this caustic effect with water?

[artupato]

Re: Water Caustics

gud evening sir damien,
can you teach us the process in making water caustic effect? ;D

[40th]

Re: Water Caustics

I know you would like that thread answered, but honestly, there's nothing special about what I did there. I just placed an omni light so that it kind of matched my sun angle, turned its intensity fairly low so it didn't affect the illumination of the scene and the caustic multiplier fairly high to counter act the low intensity of the light. I think everything else is pretty much default setups. I've lost that scene, so I really can't go back and look to see exactly what the settings are.

I've tried unsuccessfully to reproduce those water refract caustic. I placed an omni light in the scene.
here's some outputs

this one has displacement and reflection applied (no refraction).



same settings and all, only with refraction layer


omni light removed from the scene.



I see some caustics on the bottom of the pool, but they look un-proportional with the surface waves/displacement.
Another thing a bumped in to was the color of the water, when i added refraction layer, the color was fixated no matter what i did (only removing the refraction gave back the control of the color).

[dalomar_cg]

Re: Water Caustics

Oh, 40th...so close...so close.

First, if you don't have refraction, then you will NOT get the caustics your looking for. The cool water caustics that you see are due to refraction, so unless you add that to you're material your tests will be grounded before they even get started.

Second, you actually have caustics going in that scene and they are from the omni light. If you look closely on the back wall of the pool you will reflective caustics. They are faint, but they are there. Chances are you just need to bump up the global caustics multiplier in order to get them more visible.

As to what happened once you did add the refraction layer, what you're seeing is either 1 of 2 things. Either A) those are the photons from the sunlight, in which case, go to the sky settings and set the sun photons to 0 or 1, then try again. I think this is probably it because those photons are normally so faint to begin with, setting the multiplier higher has caused them to be much more visible. B) those are GI caustics, in which case disable them in the Indirect Illumination rollout.

Lastly, I think you'll have more success getting a good result if you actually have the geometry there, so using displacement rather than bump might be a better way to go.

Keep experimenting...I don't think you're too far away.

[40th]

Re: Water Caustics

The none refracted water image was to demonstrate the diffuse color, which changes dramatically when the refraction is applied.
I mentioned in previous post that the water has displacement (you can see it on the water surface edges)
Notice the color of the water on the Chrome ball reflection, its white (as it meant to be).
It appears that the size and hight of the water displacement doesn't effects the size of refracted caustics.

[40th]

Re: Water Caustics

All credit goes to Damien.
For adjusting my scene and sending it back to me fixed.
I went trough each adjustment and manually reconstructed my scene to be similar.
Attached link to the skp file:

Download SketchUp Model



I suggest to move this thread to "Tips, Tricks, and Tutorials" forum

[remon_v]

Re: Water Caustics

wow I just tried the scene and this is awsome.... finally some working caustics! thanks 40th and Damien.

[thomthom]

Re: Water Caustics

Thanks for sharing.