Category: 3D

3D, Drone, Image Processing, Optics, Photogrammetry, UAS

Inventorying linear assets– really high resolution orthos

I have been contemplating all sorts of varied uses of Structure from Motion techniques. One of those outputs, in addition to using sUAVs (drones) is just to orthorectify and generate 3D meshes from ordinary photos. This has really great potential for linear assets like streams and rivers, trails and roads. We’ll have to being to contemplate how we’ll use (and summarize!) the incredible amount of … Continue reading Inventorying linear assets– really high resolution orthos

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3D, Bundler, Camera Calibration, Drone, Image Processing, Optics, Photogrammetry, PMVS, UAS

Short follow up: Photogrammetrically Derived Point Clouds

In my previous post, https://smathermather.wordpress.com/2014/02/04/big-dmn-post-photogrammetrically-derived-point-clouds/, I briefly cover software for creating photogrammetrically derived point clouds.  I didn’t summarize, like this, but PDPCs can be created in three easy steps: Structure from Motion for unordered image collections Clustering Views for Multi-view Stereo Multi-view stereo (dense point cloud reconstruction) But, unfairly, I gloss over some of the complications of creating meaningful data from PDPC processing. Truth told, … Continue reading Short follow up: Photogrammetrically Derived Point Clouds

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3D, Bundler, Camera Calibration, Drone, Image Processing, Optics, Photogrammetry, PMVS, UAS

Big d@mn post: Photogrammetrically Derived Point Clouds

I chatted with Howard Butler (@howardbutler) today about a project he’s working on with Uday Verma (@udayverma @udaykverma) called Greyhound (https://github.com/hobu/greyhound) a pointcloud querying and streaming framework over websockets for the web and your native apps. It’s a really promising project, and I hope to kick the tires of it really soon. The conversation inspired this post, which I’ve been meaning to do for a … Continue reading Big d@mn post: Photogrammetrically Derived Point Clouds

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3D, Analysis, Database, Drone, Other, Photogrammetry, PostGIS, PostgreSQL, SQL, UAS

2.5D TINs in PostGIS

(edited: changed TIN to TIN Z) (edited again — function already exists as a flag in ST_DelaunayTriangles… .) Uh, I wrote a function for nothin’… As Regina points out in the commments, this functionality was rolled into 2.1 with a flag. Her example: For the record, my code is about 2% slower on a dataset that takes ~50minutes to triangulate . —————————————— Original Post —————————————— … Continue reading 2.5D TINs in PostGIS

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3D, Analysis, Database, Drone, Image Processing, Optics, Other, Photogrammetry, PostGIS, PostgreSQL, QGIS, SFCGAL, SQL, UAS

UAS (drone) Footprint Geometries Calculated in PostGIS with SFCGAL — for real this time

In my earlier post, I made a claim that SFCGAL was used in this figure: It dawned on my afterwards, while I was using 3D, I hadn’t actually employed any of the analysis goodies that come with SFCGAL.  Well, here it is– a footprint as calculated using the view angles and a real terrain model: Here it is compared with the initial calculation: Continue reading UAS (drone) Footprint Geometries Calculated in PostGIS with SFCGAL — for real this time

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3D, Database, PostGIS, PostgreSQL, SQL

Aaargh! No: geometry ST_RotateX(geometry geomA, float rotRadians, geometry pointOrigin)

Edit– Code may be flawed, testing—– testing. Please wait to use… . In PostGIS, ST_RotateZ has a couple forms: a version that rotates around 0,0 and a version that rotates around a point of origin: ST_RotateX and ST_RotateY have had no equivalents– until now. These equivalents are dumb versions– they use a transformation/rotation/reverse-transformation to do their magic, which is maybe not as efficient as using … Continue reading Aaargh! No: geometry ST_RotateX(geometry geomA, float rotRadians, geometry pointOrigin)

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