Archive for the ‘opengl’ Tag

Dome projection   5 comments

I have been interested in projection on spherical domes for a while, but never had the chance to experiment on an actual dome. This situation changed after I met Dave Pentecost a couple of years ago. Dave is an advocate and practitioner of the use of digital domes in education and art, and has been documenting his advances in the development of a low-cost dome authoring and projection system in this website. A dome system following those specifications is being installed at an amazing place in New York, the Lower Eastside Girls Club, a Center for Community for girls and young women on the Lower East Side. The Girls Club has been running since 1996, but recently moved to a brand new building that includes the 30 feet hemispherical planetarium, among many other facilities. A recent visit to the Girls Club’s planetarium allowed me to test the code I wrote earlier for dome projection (and realize that it was wrong), and discuss with Dave how we could use Processing and other software tools to allow people to easily create visual content for domes and to carry out artistic projects specifically tailored to the context of the planetarium. These tests and discussions lead to some recent technical developments that I will describe in more detail below.

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Posted September 6, 2013 by ac in Art projects, Programming

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Processing 2.0 is out! Processing 2.0 is in!   16 comments

Yesterday was a very important day for the Processing project, as a new stable version, “the 2.0”, has been released. This release is the result of the hard work of a small team of volunteers over the course of the past two years, plus the fundamental support and contributions from the entire Processing community. For me, this release is particularly significant since it includes a major rewrite of the OpenGL and video libraries, which represents my main contribution to the project since I become involved in it almost 5 years ago. After a long period of development, it is very satisfactory to reach a point where the code is good enough to abandon the nebulous territory the of alphas and betas. Of course, a stable release like this is also a compromise between imagination and time. Despite of the standing issues that result from that compromise, Processing 2.0 retains all the functionality that turned it into a widely used tool in computational arts, as well as adding new features and improvements that extends its capabilities and also serve as the starting point for future developments. In what follows, I’d like to describe in more detail some of the technical challenges we faced while working on the new OpenGL library, and the solutions attempted in order to deal with those challenges.
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Posted June 4, 2013 by ac in Programming

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Shaders in Processing 2.0 – Part 3   Leave a comment

This is the last part of a series of posts about the new shader architecture in Processing 2.0. This post focuses on how to integrate low-level OpenGL calls with the standard Processing API. This integration has been possible since very early releases of the 1.0 branch, and allowed users through the use of OpenGL functions to implement advanced rendering functionality not available in Processing. The main drawback of the GL integration in Processing 1.x is that it makes the sketches incompatible with regular Processing code (other 3D renderers for example), and harder to understand by many users. Although the latter will continue to be problem as long as OpenGL calls are explicitly included in Processing sketches, the compatibility issue is addressed by Processing 2.0 now that OpenGL is much more deeply integrated with the P2D and P3D renderers.
Update: With the release of Processing 2.0 final, some of the contents in this post are outdated, please check this tutorial for a detailed description of the finalized shader API.

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Posted August 3, 2012 by ac in Programming

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Shaders in Processing 2.0 – Part 1   4 comments

The new OpenGL renderers in Processing 2.0 (P2D/P3D) rely extensively on GLSL shaders. Although in most common situations the use of shaders is invisible to the user, Processing includes a new PShader class that allows to apply custom shaders to the drawing of the sketch. This post describes the shader architecture in Processing 2.0, and the common interfaces that custom GLSL shader code needs to include in order to be accepted by the OpenGL renderers in Processing.
Update: With the release of Processing 2.0 final, some of the contents in this post are outdated, please check this tutorial for a detailed description of the finalized shader API.

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Posted August 2, 2012 by ac in Programming

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OpenGL in Processing 2.0 alpha 5   14 comments

The march towards the 2.0 version of Processing reached an important milestone with the alpha 5 release, available for download since last Friday. The detailed list of changes is here, while the wiki offers a more in-depth discussion of the new features and ongoing changes. A major update in alpha 5 is the inclusion of the new OpenGL renderer for the desktop and Android modes, called P3D, which has been rewritten from the ground up in order to offer improved performance. I will describe some important elements of P3D in this post.
Update: With the release of Processing 2.0 final, some of the contents in this post are outdated, please check the new reference, and tutorials – specially those about P3D, PShape and shaders – for a detailed description of the finalized API.

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Posted March 26, 2012 by ac in Programming

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Syphon Client working in Processing   16 comments

Syphon is an OSX framework to share frames between applications. The authors of Syphon, Tom Butterworth and Anton Marini, made it very easy to create Syphon plugins for other languages, frameworks, VJ’ing and mapping tools, etc. So a while ago I wrote a simple Processing library that allowed to send frames out. This was quite useful, but still missing half of the Syphon functionality. With some additional coding, we were able to add the client part, and I just put the new version (0.4) of the Syphon-Processing library up for download (it requires Processing 2.0a4 or newer).

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Posted February 21, 2012 by ac in Programming

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At Fathom (and first tablet app)   Leave a comment

Hello! A few days ago I started working at Fathom, the information visualization studio run by Ben Fry. While here I will work on various data visualization projects, specially those requiring real-time, interactive graphics with OpenGL, as well as continue with my involvement with the development of the Processing language and environment. This job also encompasses an exciting collaboration with the lab of Pardis Sabeti at Harvard university, focused in the creation of new tools for visualizing epidemiological data and helping understand the factors that determine the origin and spread of various diseases. During my first week at Fathom I got started by working on an Android port of the “Stats of the Union” visualization, originally available for iPad tablets.

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