A new user on the World Wind forums has submitted some changes for review and inclusion into the World Wind source. It is nice to see some contributions from the community still. I picked up his changes and belatedly did a code review and tried to test them. Note this authentication just adds a username and password via the .NET Framework's "System.Net.NetworkCredential" object added to the existing request sent to the WMS server.
Unfortunately I don't have a WMS server with authentication to test his fix against. I did some basic regression testing and existing WMS functionality seems to work fine. From reviewing the code nothing appeared to be harmful and it made sense, though he added no commenting for any of the changes. I asked the user to provide more code comments as well as to finish an enhancement he was apparently making to the WMS browser for username and password fields in the browser GUI.
Forum discussion
You can get the source and see it in action from my SVN branch:
https://nasa-exp.svn.sourceforge.net/svnroot/nasa-exp/branches/ammianus
I will hold off on commiting his changes to the World Wind trunk until he responds to my questions and maybe finishes his work on the WMS Browser.
I have to say, this is probably my last contribution to the WW.NET project for now. I think it has run its course and led to a dead end, technically and in terms of a learning experience. I have begun new projects to learn more about coding in GNU/Linux and as a result want to focus my efforts towards Real-Time and Embedded system development. I have to thank the World Wind project both as a learning exercise and for the fact it did get me a job interview for a GIS programming position, and it was the first true Open Source project I made contributions to. Here's to many more.
Sunday, August 22, 2010
Tuesday, August 17, 2010
Redwoods - Day 32
Now that the seedlings have had a month to grow they have been doing well.
In general we water about twice a week, and spray the leaves and branches around every other day. The only windows in the room face east, so they get a lot of direct sun in the morning, and indirect the rest of the day. We've used some Miracle-Gro Liquid Houseplant Food, which we use for all our other house plants. In both cases starting from the bottom of the stem and growing up, the stem is turning a reddish-brown color with what seems to be the start of the redwood bark in what will be the trunk. It is only about the first 4-5 inches and after that the rest of the stem is still green like a plant's.
Specimen J2 is growing a bit fuller and maybe slightly taller. It grew a second set of branches radiating from the crown.
Specimen B2 is a little slower growing. Early on it had some "burning" of needles on some lower branches, possibly due to too much direct sunlight or under-watering. It seems to have recovered slowly but now is growing taller with more branches off the main stem.
In general we water about twice a week, and spray the leaves and branches around every other day. The only windows in the room face east, so they get a lot of direct sun in the morning, and indirect the rest of the day. We've used some Miracle-Gro Liquid Houseplant Food, which we use for all our other house plants. In both cases starting from the bottom of the stem and growing up, the stem is turning a reddish-brown color with what seems to be the start of the redwood bark in what will be the trunk. It is only about the first 4-5 inches and after that the rest of the stem is still green like a plant's.
Specimen J2 is growing a bit fuller and maybe slightly taller. It grew a second set of branches radiating from the crown.
Specimen B2 is a little slower growing. Early on it had some "burning" of needles on some lower branches, possibly due to too much direct sunlight or under-watering. It seems to have recovered slowly but now is growing taller with more branches off the main stem.
Saturday, August 7, 2010
Ubuntu Remote Desktop
Last week after installing Ubuntu Linux on a new desktop I had moderate success trying to remote into the box using vncserver.
After speaking to a co-worker I found out that Ubuntu has a remote desktop capability built in to Gnome. That was great to know, so this weekend I spent some time to set that up finally. Enabling Remote Desktop connections is as easy as going to a Preferences Control Panel, a few check boxes are you it took to set it up. See this guide for more info: Remote Access to the Ubuntu Linux Desktop.
On the Windows side, my laptop already had TightVNC client (http://www.tightvnc.com). Using the above guide it was easy to connect to the Remote Desktop on the server using the default port of 5900 and desktop of :0.
This did log me in to the Gnome desktop, and thought I could move the mouse and control the desktop through TightVNC, it would not refresh the screen in the client window. After trying out a few solutions from the Ubuntu forums that didn't work, I remembered something the same co-worker mentioned. Basically there are some issues with VNC if you have any of the desktop effects enabled.
To disable them go to:
This did the trick and my VNC client came back to life and started to function. Although it is a little choppy if you try to drag a window around the desktop it worked pretty well with the "High-speed Network" connection profile in TightVNC.
Update
Adobe Flash Plugin installed today randomly. All I did was go to http://www.pandora.com/ and install the plugin, worked fine, and the box has been serving its first function as a dedicated internet radio player in my living room.
After speaking to a co-worker I found out that Ubuntu has a remote desktop capability built in to Gnome. That was great to know, so this weekend I spent some time to set that up finally. Enabling Remote Desktop connections is as easy as going to a Preferences Control Panel, a few check boxes are you it took to set it up. See this guide for more info: Remote Access to the Ubuntu Linux Desktop.
On the Windows side, my laptop already had TightVNC client (http://www.tightvnc.com). Using the above guide it was easy to connect to the Remote Desktop on the server using the default port of 5900 and desktop of :0.
This did log me in to the Gnome desktop, and thought I could move the mouse and control the desktop through TightVNC, it would not refresh the screen in the client window. After trying out a few solutions from the Ubuntu forums that didn't work, I remembered something the same co-worker mentioned. Basically there are some issues with VNC if you have any of the desktop effects enabled.
To disable them go to:
System > Preferences > Appearence >Visual Effects
Set to "None"
Immediately this disables the "effects". The only noticeable difference is that there were some transparency effects in some of the windows, and these were turned off. This probably helps with performance in any case.This did the trick and my VNC client came back to life and started to function. Although it is a little choppy if you try to drag a window around the desktop it worked pretty well with the "High-speed Network" connection profile in TightVNC.
Update
Adobe Flash Plugin installed today randomly. All I did was go to http://www.pandora.com/ and install the plugin, worked fine, and the box has been serving its first function as a dedicated internet radio player in my living room.
Sunday, August 1, 2010
Ubuntu Experiment
I've been interested in learning about embedded system programming especially as it relates to real-time software and operating systems. This has all been spurred by my interest in the software in used by various areas of our space program ( see post Exploring the Milky Way, May 15, 2010). I did a brief search around job postings for aerospace and NASA type software eng. openings, found very little Ada, the language used to program Cassini, did find a few related VxWorks, real-time C++, POSIX C, so thought it would be worth my while to go back to programming in C/C++ on Linux environments, especially as Embedded Linux is growing in popularity[Yaghmour, Building Embedded Linux Systems, 2003].
To move towards that goal, I needed a Linux development system. I didn't want to dual boot one of my existing Windows machines and possibly deal with driver hell.
Got a machine the other day. Nothing cutting edge. AMD Athlon II X2 215 (Dual cores, ~2.70 GHz). 4GB Memory, 500GB hard disk, NVIDIA® GeForce® 6150 SE. Good thing is that the case has a slim profile, 10.4" H x 3.9" W x 14.6" D. I wanted something small and quiet so I could leave running as a server and work on remotely. It came with Windows 7 and the obligatory set of crappy trial software and spyware. Also bought a book for some programming practice: GNU/Linux Application Programming
I went with the Ubuntu Linux distribution. Created an installer CD with the 10.04 LTS 64 bit Server Edition.
Installing was a simple(!) process, the installation documentation on the Ubuntu site is pretty good, if verbose. No snags were hit, though because I chose the Server edition it didn't come with the Graphical Installer option, though its not like there were any shell commands you had to run during the install. Since I didn't care about the pre-installed Win 7 OS, I didn't have to bother with creating any partitions, I just overwrote the whole drive as one big Linux partition.
Once it booted up after install it came to the default shell prompt. There is no desktop in the Server edition. A quick google search gave me the command to install the Gnome desktop. This was plugged in
That probably took longer than the install itself. In any case it loaded up fine with a snappy new purple themed Ubuntu desktop. From start to end it was probably around 4 hours of time.
One odd thing is that during the server install you are prompted for what kind of "server package" you want to set up. I chose Java/Tomcat, though I may not even use it. I can find no evidence that Java was installed so I am not sure what that was supposed to do.
Startup now takes under 10 seconds I would say, it is incredibly smooth.
I tried to connect remotely from my windows PC using PuTTy, but no luck, there was no SSH listener running on the server. You have to enable it by installing the SSH packages.
That worked and I could connect via PuTTy SSH over port 22. Trouble is you needed to connect by the IP address of the box, you apparently can't resolve the Linux server's machine name from Windows. Fine, so I had to add an entry into my Hosts file, C:\Windows\System32\Drivers\etc\hosts. Its funny that Windows to Windows doesn't require this to resolve the machine name, but Windows to Linux doesn't work. I noticed that the Linksys router administration site did recognize the Linux server's name in the DHCP Clients Table.
In any case minor issue.
The other thing I've found is that Adobe Flash plugins doesn't seem to install, I tried the .apt and the .deb versions offered by Adobe, neither worked, getting "Architecture Not Supported 'I386'" errors. Great job Linux! I would guess it may have to do with 64-bit vs 32 as I believe Flash doesn't have any native 64 bit versions, at least not on Windows.
Next step is to try to set up VNC in order to make a remote desktop connection from my laptop to the new server. We do this at work with our Linux Oracle database host, so I know it works well.
To move towards that goal, I needed a Linux development system. I didn't want to dual boot one of my existing Windows machines and possibly deal with driver hell.
Got a machine the other day. Nothing cutting edge. AMD Athlon II X2 215 (Dual cores, ~2.70 GHz). 4GB Memory, 500GB hard disk, NVIDIA® GeForce® 6150 SE. Good thing is that the case has a slim profile, 10.4" H x 3.9" W x 14.6" D. I wanted something small and quiet so I could leave running as a server and work on remotely. It came with Windows 7 and the obligatory set of crappy trial software and spyware. Also bought a book for some programming practice: GNU/Linux Application Programming
I went with the Ubuntu Linux distribution. Created an installer CD with the 10.04 LTS 64 bit Server Edition.
Installing was a simple(!) process, the installation documentation on the Ubuntu site is pretty good, if verbose. No snags were hit, though because I chose the Server edition it didn't come with the Graphical Installer option, though its not like there were any shell commands you had to run during the install. Since I didn't care about the pre-installed Win 7 OS, I didn't have to bother with creating any partitions, I just overwrote the whole drive as one big Linux partition.
Once it booted up after install it came to the default shell prompt. There is no desktop in the Server edition. A quick google search gave me the command to install the Gnome desktop. This was plugged in
$ sudo apt-get install ubuntu-desktopThat probably took longer than the install itself. In any case it loaded up fine with a snappy new purple themed Ubuntu desktop. From start to end it was probably around 4 hours of time.
Ubuntu Gnome desktop
One odd thing is that during the server install you are prompted for what kind of "server package" you want to set up. I chose Java/Tomcat, though I may not even use it. I can find no evidence that Java was installed so I am not sure what that was supposed to do.
Startup now takes under 10 seconds I would say, it is incredibly smooth.
I tried to connect remotely from my windows PC using PuTTy, but no luck, there was no SSH listener running on the server. You have to enable it by installing the SSH packages.
$ sudo apt-get install sshThat worked and I could connect via PuTTy SSH over port 22. Trouble is you needed to connect by the IP address of the box, you apparently can't resolve the Linux server's machine name from Windows. Fine, so I had to add an entry into my Hosts file, C:\Windows\System32\Drivers\etc\hosts. Its funny that Windows to Windows doesn't require this to resolve the machine name, but Windows to Linux doesn't work. I noticed that the Linksys router administration site did recognize the Linux server's name in the DHCP Clients Table.
In any case minor issue.
The other thing I've found is that Adobe Flash plugins doesn't seem to install, I tried the .apt and the .deb versions offered by Adobe, neither worked, getting "Architecture Not Supported 'I386'" errors. Great job Linux! I would guess it may have to do with 64-bit vs 32 as I believe Flash doesn't have any native 64 bit versions, at least not on Windows.
Next step is to try to set up VNC in order to make a remote desktop connection from my laptop to the new server. We do this at work with our Linux Oracle database host, so I know it works well.
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