Terragen IOR

Started by WAS, May 16, 2020, 02:11:06 pm

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N-drju

My two cents would be - we need to base on something. If Matt has implemented the IOR feature and set water IOR value to 1.33 I have no reason to distrust him as a software designer.

I don't care that values are "off" or "in" as long as water looks like water and chrome looks like chrome.

A really basic way of looking at things on my part, I agree. But I have no time to delve into physics and molecular biology while working with Terragen. Enough said. Maybe I don't have enough of experience yet, but really... does anyone have a spectrometer and x-ray in their eyes to determine whether a texture is accurately represented or not?
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

WAS

Quote from: N-drju on May 19, 2020, 02:06:12 amMy two cents would be - we need to base on something. If Matt has implemented the IOR feature and set water IOR value to 1.33 I have no reason to distrust him as a software designer.

This is something that is variable though. 20c low oxygenated tropical water has a IOR of 1.33. Head down south towards the Antarctic with high salinity and oxygen plus much lower temperatures and you're entering the realm of 1.397 for example. Doesn't seem like much but if you're looking onto the horizon of ocean in these two zones, you can see the difference in sheen.

Matt

May 19, 2020, 02:08:24 pm #17 Last Edit: May 19, 2020, 02:11:27 pm by Matt
That's one of the reasons you can change it :)  Do you have references for that 1.397? That's pretty high.
Just because milk is white doesn't mean that clouds are made of milk.

N-drju

Quote from: WAS on May 19, 2020, 02:02:49 pmThis is something that is variable though. 20c low oxygenated tropical water has a IOR of 1.33. Head down south towards the Antarctic with high salinity and oxygen plus much lower temperatures and you're entering the realm of 1.397 for example.

That's obvious, sure. It is up to an artist to decide about the "conditions" they have in a render, but one has to start somewhere.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

WAS

Quote from: Matt on May 19, 2020, 02:08:24 pmThat's one of the reasons you can change it :)  Do you have references for that 1.397? That's pretty high.

I believe it was on the IOR info website? May have been another one. I also been reading individual studies, which is where I found IOR of water varies substantially with different salinities, oygenation and between liquid and solid phases (such as high salinity moving ocean water being kept liquid when in other conditions it would freeze). The IOR mentioned may have been a different wavelength as a lot of charts allow you to adjust, which we don't have in TG (and I'm not even sure what the default is or how it's modulated etc)