Fog Scale Dependant/Independant

[jujubee]

I've spent the last three frustrating hours trying to figure out why I couldnt make blue glass with Fog. Daforce suggested scaling the scene (which mine was done to proper US scale in feet and inches.) As soon as I scaled it to 1200% the color was effected differently by the same fog values and it turned to the blue which I wanted (altho this was not visibile in the mat preview either.) Scaling it back down made it clear then bumping up the Fog high turned it blue again.

So seeing fog value depends on which size you model your models too, perhaps there should be some notice to users or perhaps this could be readjusted to be scene/model scale dependance or independance.

[joconnell]

Abolutely - it'd be nice to have an option of using values between 0 and 1 for the dpeth of fog and translucency.

[vlado]

The fog color is the transparency of your object for 1 system unit of depth. E.g. if you make a box that is 1 system unit thin and you look in the perpendicular direction to it, it will look as transparent as the fog color. So naturally, the model scale has a large effect on how the fog appears. Unfortunately in 3dsmax colors cannot be tied to the system unit scale; however you can use the fog multiplier instead.

Best regards,
Vlado

[DaForce]

It does seem kinda odd tho, that he was working in US feet and inches, but he had to crank the fog multiplyer to 600 to get the same affect I had at 0.5
I was able to work this out because i imported part of his scene and it was really small and needed to be scaled up by 1200% to match the size in my mocked up scene.

I know why it works that way and it makes sense and all, but given most people would be using proper feet and inches or cm and meters or something, they would never think of cranking the fog multiplyer up to 600 just to achieve a light fog (or thereabouts) in some glass.

Maybe there is a way of letting them know in the vraylog that the fog MP will need to be cranked RIGHT up.

[jujubee]

Not to add fuel to a fire, but this is probably one of the biggest reasons why people find the fog parameters for glass difficult.

[joconnell]

I feel a tut coming on - I only just got this myself so maybe we can pool some knowledge and sort it?

[Da_elf]

maybe all you need to do is not to scale your objects in stupid ways
basically if i need to scale something up or down alot ill do it in vertex mode. ill just go in select all vertex then scale down the amount i want. this way the object scale as stated by max has not changed

[joconnell]

From what vlaod says it seems to be based on world units - I always work out my translucency effects using the measure controls in the utility panel - It'd be nice though if the fog and translucency effects had an option to do an override between 0 and 1 for the fog / translucency depth which was automatically mapped to the objects size in world units - Effectively where if there was a translucency depth of 0.5, the effect would always have a depth of half of your objects size and if it was 1.0, the effect would always be the full depth of your objects size - again this may mean that different sized objects would using the same material would be physically inaccurate relative to each other but I think that translucency is such a new effect it's mainly used for prettyness and not many people could argue about whether things are physically accurate or not.

[jujubee]

maybe all you need to do is not to scale your objects in stupid ways
basically if i need to scale something up or down alot ill do it in vertex mode. ill just go in select all vertex then scale down the amount i want. this way the object scale as stated by max has not changed

this advice is useless... seeing that most people will continue to encounter this issue still doing what they've done for years.

[DaForce]

Da_elf:
You seem to have missunderstood. There was no "stupid scaling"
The only scaling was done by me to work out what multiplyer jujubee should use for his fog.
By merging in his scene into mine i had to scale his stuff up by 1200% therefore it was easy to say you need to put your fog multiplyer on 1200% of my setting.
So when he increased his fog multiplyer to 60 or was it 600..cant remember (as mine was 0.5) his fog was then basically identical to mine.
And there was no scaling involved, both scene were in their original un-scaled states.