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Moderators: Barry Kelly, Karl Ottenstein, LaszloNagy, ejrolon, gkmethy

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By Stress Co.
#140186
This is a bit hard to explain, but I'm looking for a simple way to model the "surveyed" horizon line (skyline) of a site, in order to run a more accurate sun study (i.e., has the sun set behind the mountain ridge or the building next door).

I built a cylindrical "mask" which follows the elevation of the skyline (from a site survey that graphs the angle and bering of the skyline). The elevation varies depending on the radius of the mask, but it's easy to figure out.

The best solution I've found is to use the mesh tool. Any better ideas?

Would it be difficult to create a GDL cylinder with nodes every 5 degrees, where one could dictate the elevation of each node?

Just wondering.
Marc
Attachments
Picture-21.png
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By Karl Ottenstein
#140188
Hi Marc,

I import that actual terrain of interest from Google Earth. It is low polycount and not extremely accurate, but it can give reasonable sun results (because it is the close to the right size, and in the proper spatial position), and nice view-study possibilities when it is properly texture mapped (from Google) so that you can show the client what they will see out of their windows.

But...for some reason, I got somewhat poor and slow shadow results from Lightworks in AC ... but reasonably decent in Artlantis.

In case that helps.

Cheers,
Karl
By Foster
#140189
Karl, I wasn't aware that you can import the terrain from Google Earth... I have used it to place site overlays, but that is it. I have just now looked through the Help guide for Google Earth, but can't find any documentation on how to import the terrain... Am I missing something obvious here? The Pro version perhaps?

Thanks!
John
User avatar
By Karl Ottenstein
#140191
I need to write up an article on the wiki about it (but am locked out at the moment), or maybe a chapter in a book. ;-)

But, there are a couple of ways.

On PC, the Google Earth Connection lets you capture terrain. For a small area, this is fine, as it is built-in and convenient. But, for a large area - the three of us are in the mountains and need larger areas - I'm not happy with it because each bit of terrain is a new object and you have to make sure that you never move them out of their original positions.

On Mac and PC, SketchUp has a function to capture whatever terrain is shown in Google Earth. You can only zoom out so far and then capture is now allowed. Takes a couple of times to figure out the right zoom level. Each capture ADDS more terrain to your SketchUp model. You have to learn to overlap just enough to get continuous terrain, but not so much that you're adding unnecessary repetition.

The terrain grabbed by SketchUp (free download) gets a grayscale image map for some odd reason. So, before I move my position in Google Earth, I File > Save Image a color image of what was just captured. (I edit the image in photoshop later to brighten it up/etc and replace the image in my 3ds texture folder with the color one to end up with colored terrain.)

Once the SketchUp model looks decent, we're back to the Mac vs PC problem. On Mac, you have to have SketchUp Pro (the paid version) to be able to export the terrain as 3DS and then import it into ArchiCAD using the 3DS import 'goodie', resulting in a single object. On PC, if the Google Earth Connection add-on is installed, you can open the skp file from free SketchUp to convert the terrain to an AC object. A bit more futzing to get the color images to replace the grayscale ones for the textures then.

Finally, to locate the terrain relative to the building site, it is just an issue of repositioning the terrain roughly in 2D and then fine-tune in 3D. It requires that part of the terrain is your building site and that you have a modeled mesh/topo/boundaries or something that you can map to identifiable imagery from Google Earth.

Note: the terrain does not have to be contiguous! In SketchUp/Google Earth, you can grab your building site (for alignment) and then grab some mountain peak area to the north, one to the west, etc - all floating in space, basically, but providing the things that you want for determining your views. For sun studies, of course, you'll need to go continuous, so for Marc's illustration, the capture would look like a doughnut with the building site isolated in the middle somewhere.

Cheers,
Karl
By Foster
#140192
Karl,

Thanks for the chapter!! I really appreciate the advice. And what do you know, a PC is finally good for something! Do you have any decent snow there? If so, send some our way.

Marc, just noticed that we're neighbors.. Maybe we should head to Bozeman to ski?

John
User avatar
By Karl Ottenstein
#140193
You're welcome. Not a great snow year, but at least there is some! Come on up!

Attached is a zoomed out image from Artlantis of a site in Jackson, WY on a winter morning (as far as the sun is concerned - that green grass is just playing games with your mind!) The building site is at the lower red arrow.

The upper red arrow shows the morning sun coming through a valley to hit the site. I included only enough terrain to account for what would block the sun. In this case, I made things contiguous because of the importance of the valleys for morning and afternoon sun - and left town in just for context.

By zooming out like this, you can see better what I meant about the low polygon count from GE. This results in some pretty rectangular looking patches of illumination, and at times, fairly geometric shadows.

Cheers,
Kalr
Attachments
View from Delta flight 1625.jpg
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By Karl Ottenstein
#140195
Here's one at Schweitzer Mountain Resort in Sandpoint showing the use for determining views and/or just giving a client a bit more realistic OpenGL walkthrough. Home design is by a friend, but I did the GE stuff for him.
Attachments
schweitzer2.jpg
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By Karl Ottenstein
#140196
Finally, here's a view from space at the terrain for that Schweitzer project to illustrate non-contiquous terrain.

The red arrow points to roughly where the building site is in the Schweitzer south bowl area above the village. The north bowl is not included, since it is not visible from the home. The separate patch of hill to the lower right affects the view, and maybe insignificantly the sun on a couple winter mornings. The site has a view of Lake Pend Oreille, so a couple of patches of lake are included so that we can "see" them from inside the model and the deck that the guy is standing on in the last image.

(Note how the two lake patches to not blend perfectly - weird parallelograms. Just life with Google Earth capture.)

Rather than make all of the terrain be a single GDL object (from a single 3DS from SketchUp), I made two objects - so that I could turn the lake off just to get it out of the way when not needed.

For sun, the site is also affected by the Cabinet Mountains to the west, but they are far enough away, that it just delays morning sun, so was not bothered with. And, the client did not care about views to any particular peaks in that direction, so none were captured/included.

It really is a lot of fun ... and just beyond too cool that we can do this kind of stuff with the tools available today!

Cheers,
Karl
Attachments
from-space2.jpg