reflected / refracted caustics

[super gnu]

losbellos: thats a good point but i have a hunch my client would be dead impressed (sparkly things tend to impress them ive found )


j-bug: yes i started using vray lights, on default attenuation, but i found by switching to spotlights with inverse fallof, i had much more control, and seemed to need less photons to create a nice effect (like quarter as many )

im not at my workstation now....back on mon. do some more tests then... ta guys.

[losbellos]

Good boy, then listen and dont oppose please the solution is very simple (we target the effect) you put a spherical VrayLight above the water surface. Exclude all other objects (except water surface) from shadow casting and illum. Make the multiplier something around 5, then set how many photons should it shoot, and the caus multiplier for this light should start around 30.
This vraylight will make a bautifull caustics underwater and on the walls. Both. Balanced look. Tweak.

After you satisfied with the result you could put some photometric free point lights bellow the water surface just to light it up a little bellow. Whatever. but dont put too strong light otherwise it kills the caustics bellow.

If the light isnt enough outside put some fillight.

This works I tried out. If you have trouble I'll send you the scene for study
An andvise you better use mesh not a bump mapped fake water. Less trouble with it...

Bye,
LB

[super gnu]

that isnt a bump..its a reactor water surface... i have it set up so i can have people dive in and affect the surface... combined with some particle spray it should look pretty good... animates quite nicely..just need to up the faces for the final anim.

ill post a test anim when ive had a mo on it, doin another job while i wait for info on this one...

nice idea bout the vraylight ... it does seem like the best way to do it although id still like to know how to vary reflected and refracted caustic levels independently..

[losbellos]

in which renderer are you able to set the amount of different type of caustics? I very much doubt in any... And honesly I think there is no need for it.

[super gnu]

well in fr-stage 1 at least u can differentiate between the two.. you dont have a multiplier, but at least you can switch them on and off independantly (in fact you can do this in vray for gi-generated caustics, but not for direct light ones...) that much control at least would be nice.
i fail to see why it would be a useless feature to be able to adjust two, essentially seperate effects, err, seperately. the fact that ive come to a point where im having to look at work arounds involving excluded lights and colour mapping to get the effect i want suggests that it would be a nice button to have. i know for a fact im not the first person to ask about this so its not just me being super picky.. (flipside..i believe this is a feature u quite liked the sound of..?)

to be honest i wasnt expecting someone to say "oh theres some multiplier settings hidden under such-and-such tab"

more like

" the material properties that affect how strongly caustics are reflected are this and that, and the refractive ones depend on such and such"
the differentiation is not covered in the manual..


i mean.. they are SEPERATE properties..

[flipside]

Well super gnu is right, this would be a very nice function!! Fr has it, and I used it a lot. Many times the refraction caustics mess up your rendering.

Simple example: a wineglass rendering with caustics
You set up everything to create a nice refraction caustic pattern. But what happens, on the other side of the glass there are some reflection caustics who usually fall in a place where they mess up for example the composition, or where another object is that looks ugly because of them. A button to prevent the glass from casting reflected caustics would solve this easily.

It's like gnu says, we have that option for GI caustics in the GI settings (thank god we have it there!). It would be very logical to have the same function for direct caustics. We also have send and recieve GI seperate, so why not seperate the two direct caustic types??

I asked this many times before, and usually people say that they don't want vray to be as complicated as fr. Imo this isn't a complicated option, it actually makes the program more comprehensive. And if you don't want to use this function, you don't need to, just leave them turned on.

I hope it will be there someday

flipside