Rendering workshop - Whisky Glass

Al Hart

I added a light, made the ice cubes transparent, set Index of Refraction to 1.08 for the glass and 1.31 for the whiskey. I set the glass as "caustic" to get the interesting shadows on the ground.

I also marked the glass, whiskey and ice cubes as "thick" - meaning that they were modeled as solid transparent objects rather than using a single face for a single pane of glass.

I did place the glass in Solo's studio. The tricky thing there is that it is difficult to orbit and zoom on the object because the studio is so large. It worked better when I put the studio in a layer and left if off until I was ready to render.

solo

Al, here are the correct IOR values:

Ice: 1.310

Whiskey: 1.352

Heavy glass: 1.650

Rich O Brien

My try was abismal

But i'm just playing with Twilight to get good ice and failing each time. I downloaded the basic studio and damn that thing is BIG

Anyhow, i like the workshop and when i'm happy with the ice i'll post again.

Here's #2 ,i did PP with Photoshop, and let i cook for 2hrs

Anyone got tips on good ice in Twilight i could try? Currently using thick warped glass....

Al Hart

@solo said:

Al, here are the correct IOR values:

Ice: 1.310

Whiskey: 1.352

Heavy glass: 1.650

Thanks,

I'll try them.

I pulled the IOR off of the ice because it added too much to the rendering time, but maybe I'll give it another chance overnight. (I think the number of Hi-poly faces in the ice accentuated the effect.)

Also, I would like to find a better color for Irish Whiskey. I may have to go out an purchase some and "sample" it. (whoops - another pun)

Al Hart

@solo said:

Al, here are the correct IOR values:

Ice: 1.310

Whiskey: 1.352

Heavy glass: 1.650

I gave these settings a shot. I also rotated the glass so that some of the ice was seen directly. The ice looks pretty good.

honoluludesktop

Solo, How did you know that? Do you just remember, or do you have a spread sheet of successful settings?

Al Hart

@honoluludesktop said:

Solo, How did you know that? Do you just remember, or do you have a spread sheet of successful settings?

I was wondering that too. To get numbers that precise, he must have a measuring device where he passes light through a material and sees how distorted it gets.

thomthom

@honoluludesktop said:

Solo, How did you know that? Do you just remember, or do you have a spread sheet of successful settings?

Lots of lists available. Just search for IOR or Index Of Refraction. Here's one: http://www.robinwood.com/Catalog/Technical/Gen3DTuts/Gen3DPages/RefractionIndexList.html

solo

Nice list Thomthom, I have this ratty looking, frayed notebook that I write stuff in as I learn it, most of the time I cannot find where I wrote anything and have to use Google to relearn it.

Scratch that...I'm a genius!!

museummaker

I ended up on that same site-- its very interesting.

Anyone know of a similar table for reflectivity?

thomthom

@unknownuser said:

Anyone know of a similar table for reflectivity?

You mean for Fresnel material? Think you use the same tables...
For instance, the list includes non-transparent material, such as metals. (note - I'm a bit unsure here - but it's what I do and it seem to look ok...)

http://interactagram.com/physics/optics/refraction/
http://www.texloc.com/closet/cl_refractiveindex.html

Al Hart

@thomthom said:

@honoluludesktop said:

Solo, How did you know that? Do you just remember, or do you have a spread sheet of successful settings?

Lots of lists available. Just search for IOR or Index Of Refraction. Here's one: http://www.robinwood.com/Catalog/Technical/Gen3DTuts/Gen3DPages/RefractionIndexList.html

I guess I have a lot to learn about IOR.

What are the refraction indices for metals used for?

Metals
Aluminum 1.39
Copper 2.43
Gold 0.47
Mylar 1.65
Nickel 1.08
Platinum 2.33

Al Hart

@unknownuser said:

I ended up on that same site-- its very interesting.

Anyone know of a similar table for reflectivity?

I suspect he is looking for amount of reflection, sharpness, etc. for solid materials

And perhaps for additional reflection for transparent materials

Rich O Brien

Still struggling on this one

Not happy with the WhiskEy but i'll keep at it

Whiskey II.jpg

Al Hart

@unknownuser said:

Still struggling on this one

Not happy with the Whiskey but i'll keep at it

Much better than the first rendering. Nice ice this time.

Did you change the color of the Whiskey?

Try pouring it put and refilling the glass.

Rich O Brien

Didn't change anything?

Must be my choice of 'Glass' for the Whiskey, but i'll keep with till i get good feedback

thomthom

Another thing: how is the glass modelled?

Was doing some test over at the ASGVis forum, playing around with caustics. Learned that when rendering glass with liquids, the liquid inside the glass also needs to be a "solid", with the surfaces between the liquid and the glass slightly offset (to avoid z-fighting).

thomthom

@al hart said:

What are the refraction indices for metals used for?

I've used them in the reflection layers with fresnel maps. (...not quite sure if this is correct though..)

Gaieus

Well, it probably depends on the software. AFAIK Majid once made a nice description of this (that was Kerkythea) where he said that when there is the liquid, you use that material insteadof the glass material. Face orientation is very important of course (and even more of course, I am not even sure what I am talking about and whether I remember correctly)

Rich O Brien

@thom

I'll try that later, thanks for the tip

@gaieus

have you tried this out on Twilight? When you mention material rather liquid, which material in particular?

@the world

aaaaaaaaarrrrrrrgggggghhhhhhhhh!