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Old 02-20-2020, 11:17 PM   #1
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Default Smoke/Fog density and Penetrating Vision

Penetrating Vision will let you see further through smoke or fog since its "stuff" but how far? How much smoke and ash in the air counts toward that 6 inches a level? Seems like a hard thing to calculate, so Im curious what others think.
As a cop-out for gameability I am thinking its fair to say each level halves the Vision penalty for this. Sound good or not?
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Old 02-21-2020, 12:21 AM   #2
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Default Re: Smoke/Fog density and Penetrating Vision

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Penetrating Vision will let you see further through smoke or fog since its "stuff" but how far? How much smoke and ash in the air counts toward that 6 inches a level? Seems like a hard thing to calculate, so Im curious what others think.
As a cop-out for gameability I am thinking its fair to say each level halves the Vision penalty for this. Sound good or not?
For the sake of simplicity, I'd probably just replace all references to "6 inches" with "1 yard/hex". I think that's probably a good enough approximation.
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Old 02-21-2020, 12:36 AM   #3
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Default Re: Smoke/Fog density and Penetrating Vision

Penetrating vision is silent on how you're supposed to interpret its effects when looking through diffuse objects. If we assume it takes a total of 6" thickness of droplets, based on this, droplets are under a millionth of the total volume, so that gives us a vision distance of 6" x 1,000,000 or about 100 miles, or 1 level basically permits ignoring any reasonable amount of atmospheric haze.
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Old 02-21-2020, 12:47 AM   #4
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Default Re: Smoke/Fog density and Penetrating Vision

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Penetrating vision is silent on how you're supposed to interpret its effects when looking through diffuse objects. If we assume it takes a total of 6" thickness of droplets, based on this, droplets are under a millionth of the total volume, so that gives us a vision distance of 6" x 1,000,000 or about 100 miles, or 1 level basically permits ignoring any reasonable amount of atmospheric haze.
Powers covers it in more detail. P. 66
Penetrating Vision can look through multiple objects with a total thickness no greater than its penetrating power. Distance has its usual effects, but the spacing of the barriers is irrelevant. For instance, Penetrating Vision 1 can look through six 1” walls as easily one 6” wall, and these can be any distance apart – but a large total distance would still give a Vision penalty.

Nice bit on the fog and cloud thing, thanks. I have seen it used for Ice Vision and think I saw it for water vision like the magic spell but might be wrong.
Water has a lot of sediment, plankton, etc in it, especially salt water. You can see much further in a swimming pool for example or some small lakes.
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Old 02-21-2020, 03:38 PM   #5
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Default Re: Smoke/Fog density and Penetrating Vision

When looking through stuff on smoke it appears opacity is measured in meters but I'm not find data I can confidently use in this regard.
Some density calculations are helpful too. Enough material in the air to count as 6 inches thick should be a pretty hefty breathing penalty.

On the other hand, part of the above obscurement is blocking light getting to what you want to see, even if you can ignore the blockage between you and your target. Penetrating Vision wont let you see inside something if there is no light there and recommends Clair-sentience for that.
Seeing through clouds or fog should be no penalty as the subject is still well lit. Smoke and dust clouds would only be a factor if its blocking the light source or incredibly thick.

How does this look?
Penetrating Vision can help see through dust, smoke, haze, and other particle obstructions in transparent mediums such as air and water. When trying to see hexes obscured this way each level reduces the vision penalty by half or can clearly penetrate up to 6 hexes -1 hex per penalty to breathe, minimum of 1 hex.
Even one level is enough to ignore penalties from clouds, fog, and typical haze.

Also as written you cant really use Penetrating Vision to see a broken bone, or even whats in a pocket or under thick clothing. Though you could probably read a letter inside an envelope, though you may have to flip it around a few times.
All that can be done with Clairsentience and to a range of 10 yards (Clairvoyance would cost 40 points), though there are some drawbacks in that you have to change viewpoints (bought off with Aware or Second Nature) and it takes a minute (bought off with Second Nature or Reduced Time) to use.
Those drawbacks probably make up for the difference in cost and effect. But still X-ray vision seems to need something extra.
Should Penetrating Vision let you see inside a pocket or a broken bone? Should we add Dark Vision with an Accessibility limitation?
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Old 02-21-2020, 04:07 PM   #6
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Default Re: Smoke/Fog density and Penetrating Vision

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Water has a lot of sediment, plankton, etc in it, especially salt water. You can see much further in a swimming pool for example or some small lakes.
That doesn't matter for droplets. Even totally clear water droplets will make vision impossible on short order, because each droplet bends light passing through it. It's like looking through a million badly focused lenses. This is also why grinding up a clear substance (e.g. glass) produces white powder.

In terms of opacity: the standard definition of visibility is a 95% contrast resolution, which means the average path through the space is will hit 3 particles (somewhat adjusted depending on wavelength vs particle size); at smoke particle sizes, that's probably around 3 microns. 6" is ~150,000 microns, so it multiplies visual distance through smoke by 50,000, which is, again, enough to pretty much ignore any realistic level of atmospheric haze.
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Old 02-23-2020, 03:20 AM   #7
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Default Re: Smoke/Fog density and Penetrating Vision

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Penetrating Vision wont let you see inside something if there is no light there and recommends Clair-sentience for that.
. . . and only today I have learned that Superman has Clairvoyance and not Penetrating Vision for seeing people's lung state.
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Old 02-23-2020, 10:30 AM   #8
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Default Re: Smoke/Fog density and Penetrating Vision

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. . . and only today I have learned that Superman has Clairvoyance and not Penetrating Vision for seeing people's lung state.
Weird, I remember reading something that said just the opposite, that clairvoyance (in GURPS) needed light to see by, unless modified. The writeup for Penetrating Vision in the book does say that it 'automatically works in conjunction with all your other vision advantages,' and Superman has enough that he shouldn't have a problem.
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Old 02-23-2020, 11:09 AM   #9
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Default Re: Smoke/Fog density and Penetrating Vision

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Weird, I remember reading something that said just the opposite, that clairvoyance (in GURPS) needed light to see by, unless modified. The writeup for Penetrating Vision in the book does say that it 'automatically works in conjunction with all your other vision advantages,' and Superman has enough that he shouldn't have a problem.
Yeah, I'd say he has Hyperspectral vision and as you say Penetrating Vision works with all the visual senses. Clairvoyance in GURPS hpwever clearly states it can see inside with no light. p. B42 says...
Your vision
ignores darkness penalties completely.
You cannot see through solid objects,
but if your viewpoint were inside (for
example) a closed chest, you would
see what was inside despite the lack of
light.
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