Tool to generate heights of buildings from the known x or y dimensions by drawing x or y and z on street view?

[Geoffrey Zub]

I was thinking this would be an easy way to generate the heights of buildings on google maps to add the pseudo-3d views.  If we know the X or Y and we draw one of them with the height on the street view of an image we should be able to calculate an approximate height of the building by using the x to z or y to z ratio from street view and the actual x or y size in the 2d maps?

Not sure if I did a good job explaining this, but wanted to see if there was a tool like this out there or if it could be added to map maker...  This would create a relatively trivial way to create heights and should be accurate enough for the pseudo 3d which is shown in navigation and map view...

Geoff

[rjhintz]

If I understand what you're saying, this would depend distance of the street view camera from the building, would only work in areas where the imagery was of the highest resolution, and be applicable to buildings no more than about 10 stories (so you could be the top).  It might be simpler to count floors using windows and estimate 10 feet per floor.

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Rich

[Mxx]

you mean exactly the way Google Building Maker works? ;)

[Jeffrey Carpenter]

Yes, Google Building Maker does that, but I would like to have a way to build in a place that doesn't have a building views available. Like smaller towns. Currently there is no way to create 3d buildings in places without the "building view".

[Jaxcoffee]

Actually there is. Using the 3D design program called SketchUp. You can use any source, for photo texturing the buildings, without relying on views from Street View or aerial imagery.

[Geoffrey Perez]

The buildings from Building Maker do not translate into the buildings in Google Maps. They are made for Google Earth. If you compare the renderings of the TransAmerica Pyramid in San Francisco, they are completely different in GE and GM. It's probably because of the isometric view and the differences in projection, since GE has terrain and GM is flat. There would also be some difficulty with buildings set on slopes, like where the second floor on one side of the building is the same as the ground floor on the other side.

[Mxx]

i think these are minor issues that Google could figure out how to fix. All they have to do pretty much is just render those models in wireframe form w/o any textures..\

alternatively they could combine MapMaker and BuildingMaker into one tool and adjust it in such a way that people can select to build either photo-realistic models or simpler wireframe models.

[Jaxcoffee]

The Google Earth plugin does allow for viewing of 3D buildings within Google maps. The information available off of the models, as far as model information and Google Places page information, is not clickable like it is in Google Earth. Not yet anyway!!

[Geoffrey Zub]

Kind of how building maker works, but so it could work anywhere there is streetview images...  The distortion of streetview and the lack of angle for satellite makes it impossible to use those to construct accurate 3D buildings which is why Building maker is only allowed in areas with 45 degree imaging...  I wanted to use the 2D satellite image which should be reasonably accurate to get a dimension of the building and then use the streetview which is relatively distorted and probably cannot provide accurate dimensions to generate the height by using it to create a ratio which would then be multiplied by the previously measured 2d dimension. 

Would not be perfect but for smaller building (4 stories or less) would probably produce a more accurate height then assigning an arbitrary height to each story....

That actually brings up a new question which is why I am looking for a good way to estimate height, how accurate are we expected to provide height for buildings in mapmaker?

Geoff

[Jaxcoffee]

I have had a few buildings questioned based on height, or number of floors. So once that information is entered, it becomes questionable. Even when I have stood right next to the building in question, and know of the accuracy of what was stated, it was still questioned.

Just to avoid the issue, I no longer add height or floor numbers to building foot prints.

[Geoffrey Zub]

Yes, but if you add height, then you get the pseudo-3d buildings in maps, and in the android navigation application like major cities...  The one building I have added I was not questioned on the height, but want to find an easy way to come up with the heights for the buildings as I do not have a good source for the height data other than going out and physically measuring the buildings...

Geoff

[Nickvet419]

I think it would be easiest if there was a default height for numbers of floors.   It is easy to figure out the floor count. 

 Lets say for each floor, there is a default height of 15ft. and the 3D building is rendered.

 If the height field is entered, then the building would be rendered with that field rather than the default floor count.

[Will / NeoPhoenixTE]

Oh, I actually have a way of figuring out heights on buildings that's been pretty accurate with around a 2-3' variance when I actually do find a number later on.

I took the time to determine how tall a typical doorframe is on or in a building. It looks to be ~7' tall after measuring in person around my office and apartment. There's maybe a 1 or 2 inch variance, but when you're talking building heights, I doubt we're gonna care about a few inches here and there.

In street view, when you move the zoom cursor out far enough, it sets itself against an invisible wall. Sometimes the street view is smart enough to place it against the building wall if it's close enough. Here, lemme post a pic..

That square inside the orange box appears when the cursor is pushed to a wall in street view

Place that square plane that the cursor makes against a building with a doorway. 98% of the time, that square has been the exact same height as the door frame.

Funny enough, I think I picked a door in that 2% range to use as an example. Just my luck! HAH! XD

Thanks to this little observation, that tells me that square is ~7' tall. From there, it's just a matter of counting how tall the building is in street view by number of squares in street view. Anyone who's tried to measure anything 2+ feet tall with a 1 foot ruler will know the approach to take here. Stack 'em up! Don't be afraid to leave a fingerprint on your monitor once in awhile. ;)

I just count the squares, and guesstimate the remainder on the last bit (very few buildings have a height divisible by 7), and use that to calculate a rough estimate of the height. If it's within 2' of a height divisible by 5, I typically round to the nearest 5 or 0, or what seems like a reasonable number for this building.

Typical heights I've found are 15', 25', 125', and the occasional 22' and 27' in the US.

This is the most sane approach I've devised short of going to the building myself with a tape measure or actual professional measurement systems that likely cost hundreds. I'm keeping the amount of money I spend on MapMaker as low as I can until I see a check back from it. ;D

Also, some county property records get a height of buildings on file. Anyone who relies on the public data in some counties' GIS records may find that little fact useful when adding building heights.

I personally avoid adding heights to buildings that will not render nicely in 3D with a square top. Triangle roofs, round roofs, etc. Sometimes, just the outline is good enough for now. :)

at least until someone lets us at the internal tools for mapping the 3D layer.... >_>

[Greg Noel]

@Will / NeoPhoenixTE:

I took the time to determine how tall a typical doorframe is on or in a building. It looks to be ~7' tall ...

Generally true, but for some reason, my last two houses have had eight-foot doors.  I don't know why, but the developers in both housing developments choose to use tall doors.  (Both houses also have ten-foot or higher ceilings, so the door doesn't go all the way to the ceiling.)  Maybe you need to measure the doors once per housing development...

[Geoffrey Perez]

Or integrates Google SketchUp's Building Maker into Map Maker... I would so like to link those POIs with those 3D buildings!

On Thu, Oct 20, 2011 at 7:36 AM, General Map Maker on behalf of Will / NeoPhoenixTE <google-...@googlegroups.com> wrote:

at least until someone lets us at the internal tools for mapping the 3D layer.... >_>

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