Liquids ---- beginners tutorial and final render pg 2.

Here is my final study on menisci of liquids in containers. The liquid in the square container is supposed to be mercury :o


Thats superb.
Great study you have there.
You know your going to have write a tutorial now right?
Great job!

Maybe I’m missing it in the image, but is there a meniscus in the liquid? I can’t see it, but maybe it’s subtle. Other than that, some of the best use of caustics I’ve seen yet.

Thanks for the comments. Its hard to visually see the curvature of the meniscus, but it does have a noticeable effect on specularity and reflection. Without menisci, to me, liquids in containers don’t look real. I found it very easy to generate the meniscus on liquid surfaces so I will write a tutorial about how to do this.

The liquid looks pretty realistic with a maniscus going in there, good job on the liquids. The glass is nice too.

What in the world is a maniscus?

its the part of the liquid in a glass that goes up and forms sort of a “lip” its most noticable in a thinner tube, because its bigger

Its the same in any container its just looks bigger in a small tube. To see it just get any glass of water and have a look where the water meets the glass.

Can you show a profile view of the cups so that we can see the maniscus?
I know what it looks like in real life I just want to see what yours looks like.

I’ll post a tutorial tomorrow. Some of the pictures will show the profile.

You might try a render with the photon cache turned off to lose the blotchy-ness on the floor/wall entity… it would be an interesting comparison with this image.

The one thot that hit me when I first saw it was that the sides of the liquid in the glasses, especially the tall green one, were reflecting. This wouldn’t be the case in real life, would it? (I know this isn’t within the scope of your “study” but it is an interesting aspect to the “fluid in a transparent container” rendering arena.) You want the top surface of the fluid to be reflective, but not the sides, really… Very nice picture, tho!

What in the world is a maniscus?

Doesn’t it have to do with the surface tension of water? You should do a study using a water bug next! (You know, the kind that “walk” on the water’s surface by taking advantage of this property of water…) Just a thot! :slight_smile:

a meniscus is caused by the tension between a liquid and a solid object. you should try to let a paperclip or a needle float on water. you should see deformations in the water surface. the same deformations occour in a glass.

Lit this with some high-resolution hdri, and it will look quite a bit more realistic.

haha kewl…love it. prince beat that one lol.

use my tut for better caustics - cause the area lamp is a bad idea (in signature) the meniscles are really capilarry action bevels - nothing terribly complicated to do - i do it alot! :wink:

Prince, stop tooting your own horn! Your caustics tutorial is hardly exceptionally useful. His look better than your horrid, blotchy shot glass caustics.

Nice try on the liquid. I think the sticking to the side of the glass effect is a little exaggerated, and the whole thing is a tad too reflective, but I like it. I would also try to get rid of the blotchy lighting.

I should have tweaked the photon settings a bit, but it was late and I didnt want to do the render again, and I kind of liked the blotchyness of the caustics. Interestingly, when examining a beaker of water in the lab the caustics where blotchy, though on a smaller scale. I think this may have something to do with imperfections in the glass surface. But really these are just excuses for slackness.

Googled this. When there is a change in refractive index then there will be reflection. The amount of reflection depends on this change and also on the incident angle of the light. With the water/glass interface the change in refractive index is smaller than the water/air interface so the reflection should be less. I totally don’t know how yafray does the calculation.

Just found out the real problem with this. The liquid mesh has moved so there is now an air gap betwee it and the glass mesh. This may explain the problem. I will redo the render.

Way to just lay siege to someone who was only trying to help. Maybe you’d like to just shut anyone down who has anything helpful to say.

Prince’s has made a useful tut.

One thing though, caustics refers to the concentration of light by curved surfaces or refractive materials, its the bright highlights seen in the image. When light passes through a glass and doesnt show up in the shadow, this is just a fault of the renderer cause it’s not set up to detect indirect lighting, hence the need for an extra lamp, the photon lamp, to generate this light.

Also this is not capillary attraction, because I am not modelling a capillary. Rather both effects, menisci and capillary attraction are due to the same effect, liquids interact with surfaces. Water wets glass, but for other type of surfaces or other liquids the interaction could be repulsive. For instance with mercury, there is a repulsive force between the glass surface and the liquid, and the meniscus is convex. This means its really hard to pick mercury up if you spill any on a floor.

The meniscus for the red liquid and the green liquid are too big for the intended size of the glass, so I will make them smaller. I think the glass having the liquid with the smallest meniscus looks the most realistic.

My hypothesis was that to make realistics liquids in containers the liquid needs a meniscus. I should also do the null experiment to prove this. It may not be true, I may be embarassed, :-|, all this work for nothing, lol

i am sorry if i toot my tut but when 40 votes say they want a tut then i think it must be needed - and i wasnt’ refering to caustics but rather the light setup - you can use the light setup and just add a 1 emit plane to mimic an cornel box look and you get better lighting and shadows - caustics are fine! :wink: