gow to get the numbers in google earth？

[Lan Chen]

i want to make some buildings around KBFI but i can't find some numbers such as building weight,height etc.

 

[hcornea]

You can use the measuring tool to assess building footprint (ruler)

There is no Google information for height, so usually this is a question of:

Research: vertical obstruction data, other web resources
Proportionality: given the WxD measurements, use a height that looks right.
Plausibility: eg height of hangar opening fits a plane, size relative to 1.8m human being etc. Standard architectural measurements 2.7m x 0.76m door opening, for example.

Weight is entirely irrelevant for scenery objects.

As they say in the Nike ads: 'Just do it.'

Sent from my iPad using Tapatalk HD

 

[Lan Chen]

You can use the measuring tool to assess building footprint (ruler)

There is no Google information for height, so usually this is a question of:

Research: vertical obstruction data, other web resources
Proportionality: given the WxD measurements, use a height that looks right.
Plausibility: eg height of hangar opening fits a plane, size relative to 1.8m human being etc. Standard architectural measurements 2.7m x 0.76m door opening, for example.

Weight is entirely irrelevant for scenery objects.

As they say in the Nike ads: 'Just do it.'

Sent from my iPad using Tapatalk HD

Google earth had scale so that I could use ruler,but in the street view I only guess what this building height.not very accury.

 

[hcornea]

You have discovered one of the many places where ART supplants SCIENCE.

This is 3D art. Unless you have blueprints you cannot make it by measuring everything.

Sent from my iPad using Tapatalk HD

 

[Hangar32]

Actually if you can see the building in street view you can determine a fairly accurate estimate of height.

1 - in the overhead view use the GoogleEarth measuring too to determine the length of one side - must be the side you see in the street view. This is you "actual length" or AL

2 - Go to Street view and using a physical ruler, hold it up to the screen and measure the length you see for that side on the screen. Call this "Screen Length" or SL

3 - Do the same for the height -measure it with your physical ruler. Call this "Screen Height" or SH

4 - You now have two ratios that must equal each other, three knowns and one unknown variable -call that unknown "Actual Height" or AH.

5 - AL / SL = AH / SH solve for AH using simple algebra AH = (AL x SH) / SL

The units you use with the physical ruler don't matter as they get canceled out in the equation.

It's only as accurate as you measure it in street view but it will get you near enough.

Hope that helps.







Sent from my iPad using Tapatalk HD

 

[Lan Chen]

Actually if you can see the building in street view you can determine a fairly accurate estimate of height.

1 - in the overhead view use the GoogleEarth measuring too to determine the length of one side - must be the side you see in the street view. This is you "actual length" or AL

2 - Go to Street view and using a physical ruler, hold it up to the screen and measure the length you see for that side on the screen. Call this "Screen Length" or SL

3 - Do the same for the height -measure it with your physical ruler. Call this "Screen Height" or SH

4 - You now have two ratios that must equal each other, three knowns and one unknown variable -call that unknown "Actual Height" or AH.

5 - AL / SL = AH / SH solve for AH using simple algebra AH = (AL x SH) / SL

The units you use with the physical ruler don't matter as they get canceled out in the equation.

It's only as accurate as you measure it in street view but it will get you near enough.

Hope that helps.







Sent from my iPad using Tapatalk HD

Thank you.I know a little because it's not easy.

 

[charlymorton]

If you can get bird's eye imagery of the buildings in Bing Maps, you could calculate the height using trigonometry, as long as you know the building's footprint.
It won't be entirely accurate due to the low resolution of most bird's eye imagery and you would adjust for the camera lens focus length, which would be a lot of guess work.

 

[Lan Chen]

If you can get bird's eye imagery of the buildings in Bing Maps, you could calculate the height using trigonometry, as long as you know the building's footprint.
It won't be entirely accurate due to the low resolution of most bird's eye imagery and you would adjust for the camera lens focus length, which would be a lot of guess work.

Bing maps?I get the image from Google map.If it is a guess work,I think Google Earth can help me,it looks like 3d in top view.I forget the trigonometry.

 

[charlymorton]

See attached screenshot on how to calculate the height.

This is a building next to KBFI, I've measured the width of the building to approximately 32.50 metres using SketchUp, and taken a screenshot of the building using the Bird's Eye feature in Bing Maps.

Using an imaginary triangle (light blue), I've measured the adjacent side to be 27 pixels and the opposite side to be 229 pixels, which means the base of the building (hypotenuse), should be 230.58620947489466027535727785427 pixels wide. (Calculation: SQRT((27 * 27) + (229 * 229))

This means each pixel is approximately 0.14094511581595028134190542656134 metres.

You then calculate the height using another imaginary triangle (orange), where the adjacent side is 3 pixles and the opposite 29 pixels, which means the height is approximately 29.154759474226502354370764387728 pixels, and as we know the size of each pixel, this would mean the height of the building is 4.1092209506810281058352554672897 metres.

However, and this is where the guess work comes in, we have to adjust for the camera focus length and more importantly the view angle; the lower the view angle, the better.

We also have to take into account that the ground might not be perfectly level.

Also, the higher resolution the image is, the better, so you can use a combination of measurements from Bird's Eye photos in Bing Maps and Streetview photos in Google Maps.

In this case, if measuring the height of the building using the method above, with a screenshot from Google Streetview, the height is 5.454143 metres.

Because the Google Streetview screenshot is from almost ground level, this measurement is more or less pretty spot on.

But, because we now know the height ratio between Bird's Eye and Streeview photos (5.45414314 / 4.1092209506810281058352554672897 = 1.327293715), we can get the height of all the other buildings using Bird's Eye photos as long as we adjust it with this ratio. It would be fair to assume that the ratio between calculated height in Bird's Eye photos and the real height is more or less the same for the whole airport and it's surroundings.

 

[Lan Chen]

Like the A²+B²=C²？？A.B are the right-angle sides and C is the bevel edge side??It's the Pythagorean Theorem.

 

[charlymorton]

Yes, that's the one, remember to adjust for the angle of the bird's eye photo.

 

[Lan Chen]

Yes, that's the one, remember to adjust for the angle of the bird's eye photo.

But how to get how much pixels are there?

 

[charlymorton]

You measure it in any photo editor. MS Paint is good enough for this.

 

[Lan Chen]

You measure it in any photo editor. MS Paint is good enough for this.

Can I use Photoshop?I don't have MS Paint.And if I use(PS),I don't know how to get the pixels information.

 

[tgibson]

http://macosx.com/forums/design-media/35430-how-do-you-count-pixels-selected-photoshop.html