Vectortiles, openstreetmap and how this can be used to create maps https://blog.cyclemap.link/ A guided tour - In my Observable Vector Tile Dissector I evaluate different vector tile provider regarding the tilesize they deliver. The limits I chose are purely random based on long experience… But what would one do to actually reduce the tile size. I will try to optimize my own vector tiles and explain... Sun, 02 Feb 2020 00:00:00 -0800 https://blog.cyclemap.link/2020-02-02-optimizing-vectortiles/ https://blog.cyclemap.link/2020-02-02-optimizing-vectortiles/ Why invisible features are important. - I was recently asked by Gretchen N. Peterson, why I recommend to adjust the buffer size around vectortiles with the zoom level. I will try to explain that in this post. Rendering Vectortiles First we have to understand how exactly vectortiles are rendered and displayed. Similar to raster tiles, vector... Sat, 25 Jan 2020 00:00:00 -0800 https://blog.cyclemap.link/2020-01-25-tilebuffer/ https://blog.cyclemap.link/2020-01-25-tilebuffer/ How to extend an existing Pi-hole instance with secure DNS. - This tutorial shows how to set up a secure DNS server in your home network, enable DNS-over-TLS and DNSSEC to protect your DNS privacy. I will also show how to test and examine the setup to make sure everything is configured correctly. This is what you need before you begin:... Sat, 11 Jan 2020 00:00:00 -0800 https://blog.cyclemap.link/2020-01-11-unbound/ https://blog.cyclemap.link/2020-01-11-unbound/ Evaluating various tools - There are several tools available for serving vector tiles. Let’s check the following: T-Rex Tegola T-Rex You need a running postgis-instance and need to specify the table that is being used: Starting T-Rex requires just a Docker container: 1 docker run --rm -ti --net gis -p 6767:6767 sourcepole/t-rex serve --dbconn... Sun, 30 Dec 2018 00:00:00 -0800 https://blog.cyclemap.link/2018-12-30-serving-vectortiles/ https://blog.cyclemap.link/2018-12-30-serving-vectortiles/ Introduction, Data Sources and Storage - As vector maps have been really successful (see maptiler example) in the last years I want to upgrade my own map and toolchain to fancy new vector tiles technology. This series of blog posts serves mainly to sort out my thoughts and hopefully make life easier for the next guy... Sat, 29 Dec 2018 00:00:00 -0800 https://blog.cyclemap.link/2018-12-29-vector-intro/ https://blog.cyclemap.link/2018-12-29-vector-intro/ This post is about using special DEM data for map creation. If you have no clue what DEM data is, read the article on wikipedia first. I use Maperitive to create my own map, optimized for hiking/biking. Right now, Maperitive uses SRTM-1 and SRTM-3 DEM data (HGT-Files). A decent description... Mon, 24 Jun 2013 00:00:00 -0700 https://blog.cyclemap.link/2013-06-24-lidar-dem/ https://blog.cyclemap.link/2013-06-24-lidar-dem/ Emulated quadruple precision - It’s been a while since my last post about the wonders of modern GPU computing with GLSL but the following concept really took a lot of time to get it to work as intended. Today I’m going to introduce emulated quadruple floating point precision (quad-single-precision) with GLSL. I will use... Sun, 12 Feb 2012 00:00:00 -0800 https://blog.cyclemap.link/2012-02-12-part5/ https://blog.cyclemap.link/2012-02-12-part5/ NVIDIA optimizations - In my recent post about double emulation in GLSL I tested the shader code on my ATI GPU. That was a mistake… Mauna pointed out that the double emulation shader does not work on NVIDIA GPUs. I checked that and it proved that this was not a single problem on... Sun, 24 Jul 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-07-24-glsl-part4-nvidia/ https://blog.cyclemap.link/2011-07-24-glsl-part4-nvidia/ Hardware double precision - Usually GPUs do not support double precision. However, since it has become popular to utilize GPUs for computations of all sorts and the introduction of languages to support these efforts (like OpenCL, Cuda) it has become more and more important to support greater precision. To improve performance of our mandelbrot... Tue, 12 Jul 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-07-12-glsl-part3-hwdouble/ https://blog.cyclemap.link/2011-07-12-glsl-part3-hwdouble/ Emulated double precision - In my last post I introduced a simple mandelbrot fractal shader with GLSL. —Unfortunately— Intentionally, the shader code uses single precision floating point variables which ensures great performance but limits the zoom factor to about 17 before the lack of accuracy of the floating point variables takes over and all... Thu, 09 Jun 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-06-09-glsl-part2-emu/ https://blog.cyclemap.link/2011-06-09-glsl-part2-emu/ Basics - In my previous GLSL post I have shown how to draw a white quad. Since this is not the greatest visual experience, I will show something more interesting you can do with shaders in this post. I have chosen the famous mandelbrot fractal. It’s nice and colorful. Quite a fine... Tue, 31 May 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-05-31-glsl-part1/ https://blog.cyclemap.link/2011-05-31-glsl-part1/ GLSL Shader App with Qt - In this tutorial we will extend the previous tutorial and make use of a Shader written in GLSL to fill our spinning quad. GLSL is a C-like language you can use to execute code on your GPU (aka graphics card). More sophisticated effects can be achieved with this technique. The... Sun, 22 May 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-05-22-hello-glsl/ https://blog.cyclemap.link/2011-05-22-hello-glsl/ basic OpenGL App with Qt - In this first tutorial we will create a simple (I mean really simple…) Qt program to render OpenGL graphics (spinning quad). I will extend the programs you find in the Qt boxes demo and Qt OpenGL examples with a separate thread that does the actual redering to be independent (in... Sat, 21 May 2011 00:00:00 -0700 https://blog.cyclemap.link/2011-05-21-hello-quad/ https://blog.cyclemap.link/2011-05-21-hello-quad/