Hot answers tagged 3d
32
Every polygon has, at a minimum, four distinct "centers":
The barycenter of its vertices.
The barycenter of its edges.
Its barycenter as a polygon.
A GIS-specific "center" useful for labeling (usually calculated with undocumented proprietary methods).
(They may accidentally coincide in special cases, but for "generic" polygons they are distinct points.)
...
18
What makes GIS stand out from graphic design and cartography is its use of quantitative reasoning and scientific and engineering principles. Let's see how this can work without getting bogged down in unnecessary calculations.
Some Facts
In GIS it is indeed useful to have a good intuition for lengths, areas, and even volumes. I'll get to that, but let's ...
17
To be honest the time frame you mentioned for the migration sounds really tight, especially if you want to research, test, evaluate and deploy!
We have recently migrated from using ArcGIS as our desktop client to QGIS. While everything you have mentioned sounds possible the biggest issue I have found is managing the storage of Raster datasets, but like Nick ...
15
1) Analyse the areas outlined with the polygons and added buffers to some of them.
Buffers are supported. For further help, we'd need to know what "analyse the areas" means.
2) Answer questions like: Does this kind of fish (represented by a layer of points) always occur near a certain rock type (represented by polygons or points).
You can check if ...
15
Well, WebGL is promising but has few features now. You can have a look to the API and examples.
From what I know, it is supported by FF4 and Chrome 9. You will find more about browsers compatibility on their website.
Javascript libraries :
http://cesium.agi.com/ and demos
To explore :
A WebGL application based on OpenStreetMap data (and CGIAR) ...
15
Yes, there is an analytical solution for this problem. The algorithm you are looking for is known in polygon generalisation as "smallest surrounding rectangle".
The algorithm you describe is fine but in order to solve the problems you have listed, you can use the fact that the orientation of the MAR is the same as the one of one of the edges of the point ...
15
To supplement @julien's great solution, here is a working implementation in R, which could serve as pseudocode to guide any GIS-specific implementation (or be applied directly in R, of course). Input is an array of point coordinates. Output (the value of mbr) is an array of the vertices of the minimum bounding rectangle (with the first one repeated to ...
13
To create cross section:
use ArcGIS, MapInfo, etc. with point XYZ data projected on either south-north or east-west plane
or use dedicated geological software to create the section (Geosoft Target, Leapfrog Mining, Rockworks, Datamine Studio, etc.) Might require some post-processing to manually add or adjust labels and text
To create 3D topo/subsurface ...
10
AutoCAD Map 3D can do floor plans - use it to create 2D and 3D floors - then floors lead to racks (servers) and racks go to device.
Each level can be pulled out in to reveal floorplans with all the equipment locations.
10
ReadyMap might be another option. Here is an example (with a bonus of Leaflet integration!) [via @LeafletJS]:
And one more with 3D overlay on the globe:
More: demos, code.
10
This is not the first time I encounter such question and generally it is asked by people outside of geospatial industry that are not familiar with cartographic theory or with practice needs (this is just my observation).
As to the question:
A "3d Globe" that you see on the screen is nothing less than just an Azimutal projection... And there is no such ...
10
3D globes and the like are very useful for visualization purposes. You can instantly see Global Level and Continental Level data, and spatial relationships and distances are easily understood.
However you don't really need a Globe for that. As SS_Rebelious has mentioned, a Globe on a Flat Screen, is basically an Azimuth Projection. For example, Just look at ...
9
From someone who is part of the "GE Generation"
Atmospheric Data
When you are visualizing atmospheric features, it is important to see a vertical profile of the atmosphere.
Sub-surface data
When working sub-surface (bore holes, or earthquakes as shown below). In the image below, magnitude is mapped to pin size, but depth is mapped (inverted) to ...
9
Not sure if standard GIS packages are going to give you what you need. You might have to get into 3D animation/visualization packages such as Vue (paid, but not too $$, maybe around $1,000 US) or Blender (open source with HUGE community). I'd love to know what the NPS used to create the flyover you referenced.
I'm currently struggling with getting real ...
9
I have created a couple of ArcGlobe videos in the past (~4yrs ago) that look to have about the same video quality as the NPS video you referenced. The key that I was told (and found to be true) was to:
use keyframes to allow the software to create the appropriate
transition between locations,
capture the video at 4x - 8x times SLOWER than you want to ...
9
Yes, it is possible but using a Python script in the console
see For geologists: 3D geological boreholes
I presented the scripts in visualizing 3D data (Z values) or data with z attribute: a solution
or QGIS, représentation 3D des couches vectorielles (shapefiles dits 3D ou shapefiles avec attributs z) avec les modules Python Matplotlib ou Visvis à ...
8
Environmental investigations are inherently three dimensional. As a simple illustration of what some environmental data might look like, here is an image from a simple 3D GIS I created (using VRML) in the '90s.
The box-like structures are buildings in an office park. The multi-colored "straws" display subsurface geologic readings taken every one to five ...
8
I think both your points sum up the A to the Q quite well.
Some examples where its useful:
Flood Analysis
Viewshed Analysis (including shadow analysis)
Sub-terrain analysis (Geology, oil exploration)
I think a key problem with 3D is the 'Google Earth Generation' (I just made that up), think that displaying everything in 3D is a good idea.
This kind of ...
8
You need to fire up either ArcScene or ArcGlobe. They are typically installed with ArcGIS Desktop so I would imagine you already have them on your machine. If you don't have the 3D extensions (as mentioned by Brad in the comments) you could try ArcGIS Explorer which is a free viewer for both 2D and 3D data.
8
I've had a bit of experience with Rockworks (ver. 14.0) and am not incredibly impressed with it. While it's fairly easy to get data into the system, generating any kind of presentation quality (let alone publication quality) diagrams was extremely unintuitive. I gave up and drew the few cross-sections I needed by hand. I also came to realize that the ...
6
ArcGlobe
http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=ArcGlobe_3D_display_environment
Lots of RAM required.
Though Google Earth might be a better option. (as comes with a flight sim)
http://earth.google.com/intl/en/userguide/v5/flightsim/index.html
6
MapServer isn't going to do anything for you. You'd have to upgrade to the latest version to even have a chance, as prior versions just stripped the 3rd dimension in the database query. Your best bet might be to try GeoServer and the KML support there and see if you can visualize in Google Earth. Or failing that, write a little PHP script to pull your data ...
6
To close a multipatch feature, it must completely enclose a volume. Multipatch features created with the Interpolate multipatch to polygon (using a surface) tool can likely not be closed. (Unless you extrude between 2 TIN surfaces which should produce a closed multipatch. Personally, I have not had a lot of success using "Extrude Between" with complex ...
6
Natural Scene Designer is an excellent tool for fly throughs. It's affordable too. However, I'm not certain about flying underground. Although, if you have sketup pro you should be able to create something.
This methodology used to work with the free version of sketchup, but doesn't anymore, it should work with the pro version. To get your terrain data ...
6
You could export your scenes to specialist 3D modelling/viewing software. This is what I usually do because the 3D viewers of most GISs are a bit limited (EDIT: in fact I'd forgotten ERDAS Imagine does stereo too but I haven't used it for ages so I can't remember if it is just anaglyph).
EXPANDED (as per Chad's request):
You need to implement a modelling ...
5
I TA for a 3D Visualization course, and in my opinion there is certainly a place for 3D visualization in GIS.
For example, bringing a DEM (Digital Elevation Model) in ArcScene (or an equivalent program) allows you to view the X, Y AND Z (elevation) values. You can then bring in additional layers that have no elevation reference and "steal" the DEM's ...
5
There is a project at https://gitorious.org/osm2blender that imports Openstreetmap map xml data and renders in in 2.5d using the open source 3d suite Blender.
An online OpenLayers example of the output can be found at http://www.anzui.de/osm2blender/openlayers/
5
You can render from POSTGIS with OSM data in 3D
http://wiki.openstreetmap.org/wiki/OSM-3D
NOTE:
"Preparing OSM data to be viewed in OSM-3D requires a lot of preprocessing steps which are done on GIScience's servers."
see the ZIMBA server
http://wiki.openstreetmap.org/wiki/OSM-3D#Servers
5
I don't use ESRI City Engine, but I do a lot of work integrating GIS into 3d or vice versa depending on your perspective. Seeing as nobody gave you an answer, here is a generic approach. What you do really depends a lot on how the model has been built and whether you can get access to it. I will assume you have access to the model or some modelling ...
5
Assuming that money is no object, then yes, you can have all three at the same time. You'll have to invest in very robust hardware and video for starters. The difference between "games" and GIS when it comes to "game like speed" is that games have the luxury of catering the environment to the strengths of the video card and memory. The real world cannot ...
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