KeyShot Forum

Hi,
I've seen this webinar : Mastering Transparent Materials in KeyShot.
But it's not clear for me about the glass with liquid inside.
I understand the liquid surface must touch the glass surface but must it be bigger or just touch ? and the above liquid also ?
Could you post it here the .obj of the glass with the 3 surfaces ? or a slide shema ?
Thanks a lot.

There ya go Finema, try one of mine ;)

https://grabcad.com/library/another-shot-tumbler-1

Martin

thanks TpwUK but in your .bip file you have only 2 surfaces (glass + liquid), not 3...

There are two ways to render liquid in a glass...

1. The liquid top is used to slice the glass inside surface. Then those trimmed surfaces are joined to create the liquid
2. The liquid and the glass are modelled as solids. Doing things this way means you have to shrink the liquid part by a very small amount or you will see where the glass and liquid surfaces touch.

Both methods are therefore imprecise when it comes to reality, as far as i am aware the first method (which i use) gives the more accurate result visually and is the easier method.

Which part of this exercise are you more interested in, the rendering or the modelling aspect ?

Martin

i'm interested by the modeling aspect in the way 1 with 3 surfaces as in the webinar...
because at this moment, i use way 2 and the top of liquid is not realistic
thanks again

NURBs or Polygon modelling ?

Martin

nurbs :)
thanks

Okay, gimme a few moments and i will model one for you - 3DM or STEP ?

Martin

3dm :)

Glass is a solid, but i have left the parts of the liquid as surfaces so you can see what was done, you can join them back together again to form a solid liquid when you are ready.

Martin

Thanks Martin,
But i would like only 2 surfaces and a solid (glass). I want to reproduce exactly the webinar, and i don't know i must enlarge the liquid parts.

You should be able to join the liquid parts as you want/need them ... Let me see if i can find the webinar you are following and i will look at how the modelling is done :)

Martin

the webinar is here : https://www.keyshot.com/learning/webinars/

Mastering Transparent Materials in KeyShot > begin 34 minutes

thanks again

Ok you need to join the Green and the Cyan surfaces to make the liquids top surface :)

Then you will have Glass, Liquid Side and Bottom surfaces and the Liquid top only surface

Martin

if i use your model i have that > (see the screenshot)

That's what i was saying about having to scale the liquid very slightly and why it's awkward rendering wise

in KeyShot, select the liquid surfaces the click position and the scale them to .998

Martin

if i do that i have >>>

ok here's mine with no scaling - my model as draughted

Start over, when you import this time, import the NURBs data and set KS to use NURBs rendering mode

Martin

yes but the top liquid is dark

here an other example >

Golden rule number one - never settle for what you first see ...Play with colours, HDRi lighting, reflect/refract settings, add a ground plane increase bounces use global lighting etc.

Here's the same model with some materials and lighting adjustments. refract altered, more bounces and better shadows with caustics. Have fun, play with settings and make it look how you want it to look. You won't break anything :)


Martin

As for the dark top, don't forget to adjust bounces, and also remember that it's standing on a surface and will be reflecting the darker shades from the bottom as well as from the top :)

Martin

thanks Martin
vut i haven"t forget bounces and all but i would like to see a picture (tray) with glass and liquid and top liquid

Quote from: Finema on June 12, 2015, 11:50:24 PM
Hi,
I've seen this webinar : Mastering Transparent Materials in KeyShot.
But it's not clear for me about the glass with liquid inside.
I understand the liquid surface must touch the glass surface but must it be bigger or just touch ? and the above liquid also ?
Could you post it here the .obj of the glass with the 3 surfaces ? or a slide shema ?
Thanks a lot.

Hey Finema.
Here's a glass with liquid consting of 3 surfaces. I've tried to do it like they shows in the webinar.
http://adobe.ly/1BahW0O

I think the trick is to have no inner glass surface where there is liquid. Then you do not need to scale anything.
Take a look at the drawing below. The blue surface (the bottom of the liquid) takes over where the red surface (the glass) stops.

Anyone, please correct me if I'm wrong.
Hope it helps.

That's method 1 as discussed earlier in the post Esben, nice glass too :)

Martin

Quote from: TpwUK on June 13, 2015, 10:36:38 AM
That's method 1 as discussed earlier in the post Esben, nice glass too :)
Martin

Thanks Martin... and Great. I wasn't sure I understood your description correctly, or if you meant the same, but you did :)

Thanks Martin and Esben.
I've understand now.....  ;)

here my last test >
i don't know why i have white scratches on the glass

It's a good looking result to me Finema - Do you mean the banding, I have seen that in real glass too, it could be down to the tessellation on import if you used raw NURBs with no render mesh. If i remember rightly you can adjust the density of the mesh under your documents properties in Rhino

Martin

Thanks Martin !!
You are right ! It a pleasure to learn with guy like you :)
thanks again  ;)

Hi Finema,

Sorry for the delayed response, but the original file from the webinar is now attached.

I've also attached a version modeled off the original Bodum double walled tumbler set, this has an extra layer of glass like it really is in production.
It was simplified for the webinar so it would be easier to see.

Thanks!

Thanks Richard - I have borrowed the model too, wanna check it out :)

Martin

Thanks a lot Richard !

here my render with this technique

Looks pretty good Finema, if you get time I am sure Richard would love some feedback regarding his webinar :)

Martin

Always in this way, if i add some ice cubes, the liquid bottom is too transparent i think...

Hi Finema, don't forget you can reduce the transparency of the liquid too :)

Martin

Yes Martin,
but i do that i lost the colour of the liquid bottom. All become too dark.
Thanks.

Ok - Then play with the refraction to counter the darkening :)

Martin