Smathermather's Weblog

Remote Sensing, GIS, Ecology, and Oddball Techniques

Archive for July, 2013

GitHub Art — Life in Development

Posted by smathermather on July 28, 2013

Ok, all playing done.  If github validates my life in the development community, I can think of no better approach.  https://github.com/smathermather

Screen shot 2013-07-28 at 12.00.01 PM

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GitHub Art — Solution found

Posted by smathermather on July 28, 2013

Thanks for the comment on the last post, Darvey.  Per the comment, this problem space is well occupied by gitfiti, a python library for putting graffitti into your commit history, ala:

Nice work Eric Romano.  Now I have Super Mario music stuck in my head… .

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GitHub Art

Posted by smathermather on July 26, 2013

I’m thinking about drawing things in GitHub’s contribution section– maybe only uploading on certain days in order to draw or write in big green pixels. Anyone done this? The slate’s almost blank for me– seems a good opportunity to start.

Screen shot 2013-07-26 at 9.21.22 PM

—–Update—–

Been done, thanks Craig Williams:

Screen shot 2013-07-26 at 9.31.50 PM

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pov-viewshed on GitHub

Posted by smathermather on July 21, 2013

GitHub week for me:

https://github.com/smathermather/pov-viewshed

More to come, but in the meantime, enjoy.

Viewshed with Trees
Viewshed, terrain only

Viewshed Summer

Viewshed Winter

Posted in 3D, Analysis, github, Optics, POV-Ray, Viewshed | Tagged: , | 1 Comment »

Code license types for public entities

Posted by smathermather on July 20, 2013

Now that GitHub allows for simple attribution of license types (yay!), for my 200th post I’d like to solicit sources for best practices on licensing of code written by and for municipal entities.

There are so many OSS licenses, where is it appropriate to assert rights/control, such as with Copyleft, vs. MIT, vs. public domain, and are State Attorney General’s offices generally equipped to address these questions?… .

I recognize this is a state by state by municipality thing– depending on municipalities ability to assert copyright in order to control license types. I’ll composite responses and post back here and in a GIST. Ping me on twitter or here.

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shape-pov on GitHub

Posted by smathermather on July 20, 2013

I am working on a project, well, I guess just read the README from the repo (a project which will require a creative rename in the future):

https://github.com/smathermather/shape-pov

shape-pov
ATM, this is a script to write shapefiles to PovRay docs for rendering. Long-term, will be a map tile renderer with 3D support and more.

Whats more? Well, while compositing in TileMill and all the Mapnik derivatives is cool, this tool will handle true material properties, including subsurface scattering, glass like tranparency, diffusion, refraction, and a range of other sophisticated optical effects. The initial focus will be on optical alternatives to compositing rather than 3D.

Stay tuned… .

BTW, will likely be ported from a BASH script to Postgres/PostGIS functions in the future. That and a little middleware glue would provide the interface to the web. This is just the (not yet functional) rapid development version.

Posted in 3D, Analysis, github, Optics, POV-Ray | Leave a Comment »

Tree Interpolator on GitHub

Posted by smathermather on July 20, 2013

I’ve shared bits and pieces of tree interpolation code (3D tree canopies from LiDAR) on this blog for a few years. I finally got things together enough to post some of this code on GitHub. Currently it has a LasTools dependency, so you’ll have to watch for that license gotcha, but I’ll be phasing out that dependency in future versions.

In the future, I’ll do the same with my viewshed work, and some other projects.

Enjoy!

https://github.com/smathermather/tree-interpolator

Posted in 3D, Analysis, Optics, POV-Ray | Leave a Comment »

Cartographic tricks and tips– making text readable, PostGIS edition, take 3

Posted by smathermather on July 6, 2013

A little more refinement to the SQL for building masking fill for hand-placed text on maps.

CREATE TABLE use_area_mask AS

-- We'll use the "WITH" Common Table Expression (CTE) here
WITH exploded AS (

-- we want each individual letter to get it's own mask, so we Union and Dump them to break them out
SELECT (ST_Dump(ST_Union(geom))).geom FROM use_area_labels
)

-- now we can create a temporary table that is a 5-unit buffer of the convex hull
,buffer_cvx AS (
    SELECT ST_Buffer(ST_ConvexHull(geom), 5) AS geom FROM exploded
    )

-- finally, we Dump these out to their own records
SELECT (ST_Dump(ST_Union(geom))).geom FROM buffer_cvx

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Cartographic tricks and tips– making text readable, PostGIS edition part 2

Posted by smathermather on July 2, 2013

I have a couple of posts number 1 and number 2 about masking for text.  One more from the actual implementation:

forest

cave

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PostGIS Cookbook in the works

Posted by smathermather on July 2, 2013

I promised not to reveal this until first drafts were all submitted, but I’m enthusiastic to say that a PostGIS Cookbook is in the works that I’m coauthoring.   Paolo Corti has the lion share of chapters, I am writing 4, Bborie Park has written a couple, as well as a nice chapter by Tom Kraft.
Read the rest of this entry »

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