Author Topic: Part II : Pole Research Team  (Read 37914 times)

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Offline spf33

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Re: Pole Research Team
« Reply #45 on: December 31, 2008, 04:48:15 AM »
...above a reflective white roof-top...

well, since nekitamo's gonna get all the heat anyway... ;)

Aug 5, 2008, 8:18pm, spf33 wrote:

"...some sort of roofing, some sort of shiny metallic hvac on top of a building?"

though depending on how recent these sat images are, i'm not seeing too many things that could reflect sunlight or even ambient light up to the drone at that sun angle. 
maybe a windshield from a truck...dunno.
« Last Edit: December 31, 2008, 04:53:33 AM by spf33 »

Offline onthefence

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Re: Pole Research Team
« Reply #46 on: December 31, 2008, 02:18:28 PM »
...above a reflective white roof-top...

well, since nekitamo's gonna get all the heat anyway... ;)

Aug 5, 2008, 8:18pm, spf33 wrote:

"...some sort of roofing, some sort of shiny metallic hvac on top of a building?"

though depending on how recent these sat images are, i'm not seeing too many things that could reflect sunlight or even ambient light up to the drone at that sun angle. 
maybe a windshield from a truck...dunno.

Maybe you are both talking about two different things:
  • The underside of the drone is well lit probably because of the white rooftops
  • The shadow directions on the drone cannot be explained by a mirrored surface on the ground since none can be found
« Last Edit: December 31, 2008, 05:51:03 PM by spf33 »

Offline spf33

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Re: Pole Research Team
« Reply #47 on: December 31, 2008, 05:51:30 PM »
Maybe you are both talking about two different things:
  • The underside of the drone is well lit probably because of the white rooftops
  • The shadow directions on the drone cannot be explained by a mirrored surface on the ground since none can be found



i can accept that the lighter colored rooftop could be contributing somewhat to the overall lightening of the drone bottom. 
but i don't discount the possibility that some sort of reflected light is possibly obliterating the arm "missing shadow";



or are you talking about the dark colored horizontal shadow on part 15 (which i'm not convinced is a shadow)? 

Offline onthefence

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Re: Pole Research Team
« Reply #48 on: December 31, 2008, 06:08:27 PM »
or are you talking about the dark colored horizontal shadow on part 15 (which i'm not convinced is a shadow)? 

It is part 15's dark area that confuses me.
  • Dark in PICT15,16
  • Light in PICT17

I don't think we can all come to a conclusion about what pieces cast the shadows on the drone in the raj pics, can we?

Offline spf33

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Re: Pole Research Team
« Reply #49 on: December 31, 2008, 06:39:33 PM »

I don't think we can all come to a conclusion about what pieces cast the shadows on the drone in the raj pics, can we?

shadows?



that dark rectangular area on part 15 always seemed to me to be just a darker colored material with a change in specular highlights due to that planes orientation to the sun.

pic16 to pic17:



a more extreme example than what's happening here, but the idea is the same:


Offline spf33

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Re: Pole Research Team
« Reply #50 on: December 31, 2008, 06:49:01 PM »
...but now that i'm looking at it.  the left side of part 15 doesn't look like it has a darker
middle area.

ok, i'm probably wrong and that area is (supposed to be) a shadow.

« Last Edit: December 31, 2008, 06:52:40 PM by spf33 »

Offline 10538

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Re: Pole Research Team
« Reply #51 on: December 31, 2008, 08:33:11 PM »
a more extreme example than what's happening here, but the idea is the same:



This illustrates what I think may be happening.  Also add some tilt backwards increases the effect.


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Re: Pole Research Team
« Reply #52 on: January 01, 2009, 08:33:33 AM »
Wow, late to the show myself but wow, great job on this one!!!!! Finally we get the illusive pole!!!! A lot of info will come from this.

Offline 10538

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Re: Part II : Pole Research Team
« Reply #53 on: January 01, 2009, 11:53:25 PM »
Hey Endzone,

Pretty exciting stuff, eh.  I made this from Google streetview.  Sorry I'm not a better graphics artist.




Offline onthefence

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Re: Part II : Pole Research Team
« Reply #54 on: January 02, 2009, 03:44:10 AM »
Eventually it would be nice to see the pole in similar lighting conditions to PICT16, as well as other times of day to ensure that all shadows under the crossbar are not just oil stains.

The following photo is late at night (and I had to brighten it up) from this image.



I just want to ensure that assumptions made about shadows on the pole in PICT16 are correct.

As well, the pole is angled, I'm not completely sure this has any impact on the shadows though.

Offline Arkhangels

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Re: Part II : Pole Research Team
« Reply #55 on: January 06, 2009, 04:10:55 AM »
If you guys are considering that the pole is bend like OTF measured, you should consider it in all the three axis. It appears to me that it falls in at least two different directions.
 :(

Whoooooo

Offline onthefence

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Re: Part II : Pole Research Team
« Reply #56 on: January 06, 2009, 04:16:37 AM »
If you guys are considering that the pole is bend like OTF measured, you should consider it in all the three axis. It appears to me that it falls in at least two different directions.
 :(

What kind of equipment and methods should be used to properly measure this?

And, would it even matter?

Offline Arkhangels

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Re: Part II : Pole Research Team
« Reply #57 on: January 06, 2009, 04:22:51 AM »
I dunno... when you guys were measuring distances and angles to match the shadows in the drone and pole, the tilt was important right?

Whoooooo

Offline 10538

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Re: Part II : Pole Research Team
« Reply #58 on: January 06, 2009, 05:13:42 AM »
I had been saying for more than a year that the pole was likely tilted.  One look at the angle of the power lines and the poor angle of the support cable (now we know it's because there is a drive way there) was enough evidence for me.  Too many people jumped to conclusions as usual.  It's leaning just as I imagined it.

« Last Edit: January 06, 2009, 05:16:36 AM by 10538 »

Offline nekitamo

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Re: Part II : Pole Research Team
« Reply #59 on: January 06, 2009, 12:04:12 PM »
Well, I'm afraid pole tilt was completely irrelevant for my 3D reconstruction. It could have been on a very steep slope, but it wouldn't change a thing because sun angle in software I used wasn't determined automatically, based on time and date (like in spf33's 3D Studio Max) but manually, however you want it to be (including some impossible angles, i.e. from bellow). So all I did was model the pole, adjusted the camera to match exact perspective in Raj's image and then tweaked my "sun" angle until crossbar shadow on the pole looked exactly the same as Raj's - I didn't even use any kind of ground surface until later, for some other views of the scene.

So what I'm trying to say is that pole tilt could play important role in determining exact time of day, but IMO it won't help much in explaining drone shadows because drone's orientation toward the sun in pic16 is locked by its relationship with the upper part of the pole, no matter how tilted or not - unless you're implying there was also some other, ground level related light source...