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Old 06-20-2018, 02:21 AM   #1
Benway
 
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Default Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

Two questions, by your leave:

The Unattached Agent in our game has the off the shelf bionic eye with Hyperspectral Vision. As this is a Centran device, there is obviously no mana/magic detection.

A few sessions ago he encountered a Perfect Illusion. The player actually felt that he would not be able to detect it, which by RAW is logical. Could he possibly be able to detect it by the difference in light signature, the physics of illusion, or something along those lines. Would a Perfect Illusion be so perfect that it would fool a bionic eye, or a surveillance camera?

Also, if someone with Insubstantiality is falling and goes insubstantial, Basic Set says they are not affected by gravity, got it- however, since they can move in this state could they use the momentum to effectively fly? Would they just stop dead and float in the air or slowly come to a stop? How would that work?

Thanks.
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Old 06-20-2018, 04:29 AM   #2
Nereidalbel
 
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

1. Perfect Illusion would most likely fool any non-magical detection, short of walking up and hitting it with a stick.

2. You can only change your velocity by your own move score per second, so, no flying. At least you won't go splat when you reach the ground.
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Old 06-20-2018, 05:45 AM   #3
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

What do you mean by "effectively fly"? An Insubstantial character can move through the air with no means of support, including up over the ground, passing between upper stories of buildings or over chasms. That's "effectively flying" in some sense. However, the character is using their Ground Move (important if they want to buy Enhanced Move to go faster), and they'd use Acrobatics skill rather than Aerobatics. For mechanical purposes, they're "not flying". (They're just Ground Moving with style.)

The idea seems to be trying to be logical about ghosts, at least in some ways. If they always pass through solid matter, yet were affected by gravity, they'd all fall to the center of the earth and be stuck there. They wouldn't be able to go up stairs, because they couldn't push down on the stair to push themselves upward. So, they don't need support from the ground. Insubstantial doesn't include Flight for free, though. It's not even really material, or "on this plane" (whatever your fluff text is), so their earthly environment isn't important to their regular Move. They can just move in any direction in their unobstructed ethereal plane, and that looks like whatever it looks like on Earth, whether that's "going up stairs" if the ghost happens to ascend, ethereally, at the same rate as the stairs, or "flying" if the ghost is moving horizontally at a constant three feet above the floor.

Search the forum and you'll find arguments about whether Insubstantial characters can ride in vehicles, particularly ones that are much faster than they are...
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Old 06-20-2018, 06:06 AM   #4
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Originally Posted by Benway View Post
Two questions, by your leave:

The Unattached Agent in our game has the off the shelf bionic eye with Hyperspectral Vision. As this is a Centran device, there is obviously no mana/magic detection.

A few sessions ago he encountered a Perfect Illusion. The player actually felt that he would not be able to detect it, which by RAW is logical. Could he possibly be able to detect it by the difference in light signature, the physics of illusion, or something along those lines. Would a Perfect Illusion be so perfect that it would fool a bionic eye, or a surveillance camera?
Illusions can fully be used to fool things like security systems that rely on the senses that the particular illusion covers(all but touch in case of perfect).

Basically if the hyperspectral vision helps depends on your reading of things like artist(illusion) that seems to imply that a illusion is not automatically believable, but instead requiring a skill roll.

Personally as a GM I do quick contest of artist(illusion) of the creator vs perception of the observer to see if there are something illogical or wrong that is spotted. I use large modifiers depending on how suitable the illusion is to the situation and how actively the observer is observing. I give +3 for Hyperspectral Vision for the observer side.
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Old 06-20-2018, 06:13 AM   #5
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Originally Posted by Nereidalbel View Post
1. Perfect Illusion would most likely fool any non-magical detection, short of walking up and hitting it with a stick.

2. You can only change your velocity by your own move score per second, so, no flying. At least you won't go splat when you reach the ground.
You mean you can only move your move score by second, yesno?
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Old 06-20-2018, 06:30 AM   #6
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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What do you mean by "effectively fly"?
Say the character is falling 60 feet and goes insubstantial at 30 feet. If he were to continue to fall and then, for instance, bank to the right in a more horizontal direction he might appear to be "effectively flying."

It seems that he would no longer accelerate toward the ground. So then would he stop, slow down or continue to move at the same rate, or his move rate, which falling at 32 ft per second per second would also make him appear to decelerate?

I have to dig up that discussion on Insubstantiality in vehicles. Very interested in that. For Rule of Cool's sake I would allow for an enhancement; one that could be acquired in-game.
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Old 06-20-2018, 06:34 AM   #7
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Originally Posted by weby View Post
Personally as a GM I do quick contest of artist(illusion) of the creator vs perception of the observer to see if there are something illogical or wrong that is spotted. I use large modifiers depending on how suitable the illusion is to the situation and how actively the observer is observing. I give +3 for Hyperspectral Vision for the observer side.
I'd give that +3 if the creator of the illusion was aware of the existence of hyperspectral vision, and tried to allow for it. If they weren't, the illusion would be obviously flawed to anyone with hyperspectral vision. If the creator had hyperspectral vision, the roll to detect their handiwork as an illusion would be the same as if you were just using normal vision.
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Old 06-20-2018, 06:37 AM   #8
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Originally Posted by Benway View Post
A few sessions ago he encountered a Perfect Illusion. The player actually felt that he would not be able to detect it, which by RAW is logical. Could he possibly be able to detect it by the difference in light signature, the physics of illusion, or something along those lines. Would a Perfect Illusion be so perfect that it would fool a bionic eye, or a surveillance camera?
Spells have no physics. They do what they say they do whether it makes sense or not. And yes, Perfect Illusions fools any sense but touch. For that matter Simple Illusions are visual and Hyperspectral Vision is a kind of vision - they would work too. Nothing in the spell descriptions requires the caster to have, or even know anything about the senses fooled. And yes, Perfect Illusions will fool infrared or heat senses despite the fact you can't warm yourself with a Perfect Illusion fire even if that makes no sense.

Quote:
Also, if someone with Insubstantiality is falling and goes insubstantial, Basic Set says they are not affected by gravity, got it- however, since they can move in this state could they use the momentum to effectively fly? Would they just stop dead and float in the air or slowly come to a stop? How would that work?
My ruling on that would be you're moving at the same speed when you change states, and would need to consciously slow down if you wanted to stop, but given that GURPS movement rules mostly don't require acceleration or deceleration times, you probably could stop dead on your next turn if you want. If for some reason you want to continue to move downward, that would be fine too. I wouldn't let you change the direction of that movement vector and move some direction other than down with your falling "momentum". Of course being insubstantial it's not like falling will do you any harm, since you won't be hitting anything, but it's a long boring trip through the planet (several days) at terminal falling velocity.

You shouldn't read too much into "not affected by gravity". The intended effect here is more like the insubstantial plane doesn't *have* any gravity. This is just a rather poorly worded way of trying to close one of the (many) logic loopholes in Insubstantiality that come from trying to understand it by physical rather than narrative laws. Its much the same issue as the illusions really. Trying to apply physics to magical effects is a popular idea, but a largely nonsensical one.
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Old 06-20-2018, 07:52 AM   #9
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Originally Posted by malloyd View Post
My ruling on that would be you're moving at the same speed when you change states, and would need to consciously slow down if you wanted to stop, but given that GURPS movement rules mostly don't require acceleration or deceleration times, you probably could stop dead on your next turn if you want.
To the contrary, the GURPS rules do require acceleration and deceleration when you are moving above your maximum Move. You can only change your speed by your Basic Move - normally one does not move faster than one's Basic Move, but e.g. Enhanced Ground Move does change ones maximum speed without increasing the Basic Move - so it takes multiple seconds to get up to top speed, and it takes multiple seconds to slow down again.

I believe you can try to break hard but have to make handling rolls or lose control (which in this case would involve more falling).
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Old 06-20-2018, 08:15 AM   #10
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Default Re: Hyperspectral Vision vs. Illusion/Insubstantiality and Falling

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Say the character is falling 60 feet and goes insubstantial at 30 feet. If he were to continue to fall and then, for instance, bank to the right in a more horizontal direction he might appear to be "effectively flying."
He can continue to move down, and sideways if he wants. For that matter, he can stick his arms out to the side and lean over. But the insub character isn't interacting with the air any more than with stone walls, so "banking" isn't going to change his direction, as it generates no push. If it's stylish and cool, though, feel free. (Also declare your cloak flaps and swirls dramatically, even though there's no physical air breezing by.)

I'd use the rules for 3D movement also used for flying (e.g., 1 hex up and one hex over is 1.5 hexes of movement).

Quote:
It seems that he would no longer accelerate toward the ground. So then would he stop, slow down or continue to move at the same rate, or his move rate, which falling at 32 ft per second per second would also make him appear to decelerate?
B395 has rules for acceleration and deceleration. Basically you can change your speed by your Move. (The vehicle rules have some more detail, including gravity assist for diving for fliers and Acceleration different than Move.)

In this case, I'd treat the character as having the speed he's accumulated by falling, carrying over after he goes insubstantial. (It doesn't matter that he can't move down at that speed on his own; even ghosts might able to be pushed by ghostly forces beyond their own movement ability.) He no longer accelerates due to gravity once insubstantial, and can slow down by his (insubstantial) Move. Not that it will matter if he "hits" the ground, as he can pass right through it and pop back up once he's slowed down "underground". (Make sure the character can breathe, though. Insubstantially doesn't by default give you the ability to breathe while inside something.)
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