glas, fluids, lighting - still challenging for me :(

[t0m_smyk0wski]

glas, fluids, lighting - still challenging for me

hi guys,

I was fooling around with todds awesome Loft script a little and now I gave up after a few hours...
I find it still very challenging to set up glas and fluid materials (even thoug I found this: http://hyperphysics.phy-astr.gsu.edu/hbase/tables/indrf.html which I find kinda helpful).

Another thing I just cant seem to get right is lighting. As a scene is only really good with a nice lighting and good materials:
Can you guys give some advise, hints, tips and or tricks on glas, fluids and lighting?

attached you'll find the *.jas and a picture of the scene, which I think is just not right...
Many thanks in advance for posting your material settings and light source setups.

-t0m

 

[squareitround]

t0m

I had a look at your scene and made a few quick changes. (It's in no way perfect, and could still do with quite a bit of tweaking.)

http://mysite.orange.co.uk/macscraps/lemonade2.zip

Couple of notes about the changes and a few hints (you may already know a lot of this):

I noticed that the base of the glass is a n-gon with many sides. It is considered best to try and keep your polys 4 sided if you can, because it can sometimes creates rendering errors. It may also partly explain why the base is so black, but I didn't really look into it.
If you are making liquid in a glass, it's a good idea to make the liquid very slightly smaller than the inside of the glass. If the edges both share exactly the same space it can lead to rendering errors.
To make the bubbles look really real, you need to boolean them from the liquid so they are hollows like in real life.
Your material settings were fine - I just tweaked them a little. The main thing was to turn off specular. A rough rule of thumb is; if a material is already fairly reflective, then you don't need specular as well, because it is really just a quicker rendering way of faking slight reflection.
I added a caustics tag to the camera, which always helps make glass look better - at the expense of rendering time!
A good idea when setting up lighting is to turn off all the textures so you can do quick test renders until you are happy with the shadows/contrast etc...
The main thing with lighting an empty background scene, with a reflective object like this is one, is you need to give the object something to reflect. You can use area lights to simulate the lightboxes a real photographer would use. Also a bit of ambient lighting, the colour of the background, helps simulate the diffused light that happens in the real world. There are some tutorials here on the basics of lighting. They're for Max, but the ideas the same. http://www.computerarts.co.uk/tutorials/3d__and__animation

Phew, that's all I can think of for now! Hope it's of some help.

Cheers

Square

 

[t0m_smyk0wski]

thanks... I'll keep you posted with the progress - if I make any
-t0m

 

[squareitround]

I'll keep you posted with the progress - if I make any

You've chosen a tricky subject! Lighting glass well in a plain studio type scene is quite difficult. You can use a HDRI, which will give good reflections, but it also tends to tint the scene a colour, unless you use special studio HDRIs.