opencl

I'm starting to learn some of what needs to be done to use OpenCL by watching some podcasts here. OpenCL stands for Open Computing Language. It is a software development framework to aid doing general purpose graphics processor computing. So when applied in a program, some work is moved away from the cpu over to the graphics board across a bus. Even though moving data back and forth between the cpu and gpu is slow relative to the number of instructions a cpu could have executed on data had it not been moved, the speed of newer graphics boards with certain operations, like doing many simultaneous floating point calculations, can make the operation result in a net improvement in performance.

The Khronos group defines the OpenCL specifications. They also handle OpenGL. According to web articles both Nvidia and ATI now support OpenCL in many of their graphics boards. However I've seen some people mention problems trying to build and then get samples of the library to work with their graphics cards.

Surface Shader update on Vimeo

PQ Houdini posted an update to the surface shader of a brick. The update corrects some flaws with the previous shader.

PQ Houdini Tutorial on Vimeo

Some additional video tutorials by PQ Houdini for the 3d application Houdini are available on Vimeo. The brick shader he built in VOPs looked interesting. Many of the operators in the video were new to me, such as filter and color mixer. I haven't made much progress with Houdini since the last post, but perhaps this site will help.

Houdini and 3DConnexion Devices

A blog entry at geneome.com describes an attempt at using Python to enable 3DConnexion SpaceNavigator support in the Houdini 3D app.

He mentions a complication involving the lack of _ctypes.pyd in the Houdini Python distribution. Houdini 10 includes Python 2.5 and some commonly used modules with its 3d app, but apparently it was not enough for this project. I don't completely understand the post, but it sounds like this prevented the Python comtypes module from working, and that prevented Python from polling of the device driver using COM (Component Object Model). A workaround involved compiling the needed module himself with the Python compileall module in Houdini and then putting the binary code in the lib directory of Houdini. I'd never heard of the compileall module before reading the post and will take quick look at it later.

Another complication involved Houdini freezing during display of data from the 3dConnexion device into a window.

He posted a video of a demo to vimeo.

The post also references an odforce post with some one else's Python code that does the same thing and was apparently was developed simulaneously.

From the post:
The SpaceNavigator seems ideally suited to be able to control not just a camera but any object in 3 dimensions, provided that the application can see and understand the device.

more cg roundup podcasts

CG round up podcasts 6 & 7 are now available at www.cgroundup.com.

I still haven't gotten to listening to them yet.

A comment on one of these new podcasts mentions a blog post that does a comparison of ICE vs. VOPs. Looks interesting.

Houdini books with applied math

Some books recommended for helping learn shader writing and math applied towards graphics are listed here on a Houdini forum.

They include:
Advanced Renderman
Texturing and Modeling, A Procedural Approach
Essential Renderman Fast

Maybe later I will attempt to take a look at a portion of one of them.

odforce post

Odforce.net has a blog post about Houdini and the HDK docs. They explain that the HDK is the best way to add extra functionality to Houdini, but VEX and Python fill a need inbetween the GUI and HDK programming. I'll need to investigate this further to understand what this means. There is also steep learning curve mentioned in the entry.

PICAXE microcontrollers

I purchased some PICAXE microcontrollers recently and hope to program them later. Tonight I tried out the programming editor and logic software by writing a simple program that played a note. Also noted forum post that the 12f683 label on the chip is correct even though it doesn't match the PICAXE name for the chip.

Blog entry for an HDK project

Here is a blog entry about using the HDK that is about four years old. According to the post, he attempted to get data from a joystick into Houdini. He wrote his own CHOP (Channel operator) to do this. SDL, a game library, was used to get joystick information. The entry contains some steps he took to build and link to the HDK using Visual C++ and Windows. He mentions a plan to use Python and PyGame, but I'm not sure whether that means he got his Python code to connect to C++code because he mentions a C++ compiler.

Actually, a more recent post here describes this project at a finished stage. From the snippet of code it looks like he ended up using the C interface to SDL.

Houdini HDK

Noted that sidefx on Twitter mentions new Houdini Developer Kit (HDK) documentation is available at http://www.sidefx.com/docs.

Houdini has a Houdini Object Model (HOM) that can be accessed from Python. This link notes that together they may be used for HDK development, network rendering, and animation workflow.

From the site:

The Houdini Developer's Kit [HDK] is a comprehensive set of C++ libraries that give third party developers access tot he same API used by developers at Side Effects Software.

With the HDK, you can create plugins to customize virtually all aspects of Houdini.

Ubuntu Remix

Ubuntu 9.04 Netbook Remix is something I'm trying out. Some issues with certain models are listed here. It is free to download. The site has instructions on using win 32 disk imager to create a bootable USB flash drive. They provide a link to launchpad.net to get it. The instructions explain that a CD image file format extension is .ISO and a flash image file extensions is .IMG. 1 GB or more of space formatted in FAT32 is needed. Also, the image is the only thing allowed on the flash drive. All preexisting files get deleted. The bios settings may need to be changed to attempt to boot from a flash drive before other devices.

Python ocr and opengl libraries

I plan on looking into Python libraries pytesser and pyopengl later. Pytesser is an ocr library accessible from Python. Pyopengl provides opengl access to Python.

I've downloaded Eclipse and pydev to start with. The web site says it supports Python 2.4, 2.5, 2.6, and 3.0 syntax but that part hasn't worked for me yet.

cgRoundup

Some Houdini related things to do include checking out http://www.cgroundup.com/ and the SideFX twitter account. The title of the last cg round up post is "cgR - Episode #005 - "Meet Eugene".

Botanicalls Kits

http://www.botanicalls.com/about/

They did the original prototype with an Arduino and then went to a board that looks like a leaf.

from the web site:

Botanicalls opens a new channel of communication between plants and humans, in an effort to promote successful inter-species understanding.

The Botanicalls project is fundamentally about communication between plants and people. We are empowering both by inventing new avenues of interaction. Plants that might otherwise be neglected are given the ability to call and text message people to request assistance. People who are unsure of their ability to effectively care for growing things are given visual and aural clues using common human methods of communication.

Who are we?

Botanicalls is an ongoing collaboration between Rob Faludi, Kate Hartman, and Kati London.

Flash player update

An update for the Flash player was just released.

From the site:

Update: An alpha refresh of 64-bit Adobe Flash Player 10 for Linux operating systems was released on 7/30/09. The release versions of Flash Player 10 for Windows, Macintosh, 32-bit Linux, and Solaris are now available from the Flash Player Download Center. Please download the latest prerelease versions below.

2009 Apprentice Challenge

This is rather late, but about a month ago some people participated in a Houdini Apprentice challenge on YouTube:
http://www.youtube.com/group/3dworldchallenge

Google Trends

I've been looking for a use for Google trends lately, and today Rackspace showed up in the top 10. Apparently the web site outage affected so many people that search interest in the term jumped noticeably for that hour or so. So, I am thankful for the trends site. I was not web browsing at the time of the outage, and it was rather convenient to go to trends and find out about it. I realize the item showed up on the techcrunch blog. Perhaps that is a better solution to my search for technical news, but Google trends seems like a nice general purpose tool.