capture button under Linux broken?

[bomack]

running Alice 2.0 under openSUSE 10.3. So far so good.
Noticed today after opening up an example world that the "take picture" button is non-functional. I tried the keyboard shortcut and got an error. tried to submit error, but that produced another error. here's the button error. anyone know how to repair/fix?

Error while attempting screen capture.


Alice version: 2.0.7
os.name: Linux
os.version: 2.6.22.13-0.3-default
os.arch: i386
java.vm.name: Java HotSpot(TM) Client VM
java.vm.version: 1.5.0_13-b05
user.dir: /tmp/alice/Required

Throwable that caused the error:
java.lang.NullPointerException
at edu.cmu.cs.stage3.image.ImageUtilities.getWidth(Im ageUtilities.java:43)
at edu.cmu.cs.stage3.image.ImageIO.store(ImageIO.java :106)
at edu.cmu.cs.stage3.image.ImageIO.store(ImageIO.java :103)
at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.storeCapturedImage(AuthoringTool.java:2797)
at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.takePicture(AuthoringTool.java:5170)
at edu.cmu.cs.stage3.alice.authoringtool.Actions$34.a ctionPerformed(Actions.java:281)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1849)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:258)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEven tMulticaster.java:231)
at java.awt.Component.processMouseEvent(Component.jav a:5517)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3135)
at java.awt.Component.processEvent(Component.java:528 2)
at java.awt.Container.processEvent(Container.java:196 6)
at java.awt.Component.dispatchEventImpl(Component.jav a:3984)
at java.awt.Container.dispatchEventImpl(Container.jav a:2024)
at java.awt.Component.dispatchEvent(Component.java:38 19)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:3822)
at java.awt.Container.dispatchEventImpl(Container.jav a:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1791 )
at java.awt.Component.dispatchEvent(Component.java:38 19)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 463)
at java.awt.EventDispatchThread.pumpOneEventForHierar chy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:153)
at java.awt.Dialog$1.run(Dialog.java:535)
at java.awt.Dialog$2.run(Dialog.java:563)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Dialog.java:561)
at java.awt.Component.show(Component.java:1302)
at java.awt.Component.setVisible(Component.java:1255)
at edu.cmu.cs.stage3.swing.DialogManager.showModalDia log(DialogManager.java:58)
at edu.cmu.cs.stage3.swing.DialogManager.showDialog(D ialogManager.java:123)
at edu.cmu.cs.stage3.alice.authoringtool.AuthoringToo l.play(AuthoringTool.java:5087)
at edu.cmu.cs.stage3.alice.authoringtool.Actions$15.a ctionPerformed(Actions.java:167)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1849)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:258)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEven tMulticaster.java:231)
at java.awt.Component.processMouseEvent(Component.jav a:5517)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3135)
at java.awt.Component.processEvent(Component.java:528 2)
at java.awt.Container.processEvent(Container.java:196 6)
at java.awt.Component.dispatchEventImpl(Component.jav a:3984)
at java.awt.Container.dispatchEventImpl(Container.jav a:2024)
at java.awt.Component.dispatchEvent(Component.java:38 19)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:3822)
at java.awt.Container.dispatchEventImpl(Container.jav a:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1791 )
at java.awt.Component.dispatchEvent(Component.java:38 19)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 463)
at java.awt.EventDispatchThread.pumpOneEventForHierar chy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:110)

[bomack]

setting an objects opacity at 50% or lower also makes the object disappear instead of showing it's designated opacity.
An object's bounding window does not show up.

sigh.. I suppose i may have to go with windows? the linux version seems a bit too buggy to do any real learning... :(

[DrJim]

The opacity problem is one of several display problems that surfaces even with XP when an older graphics card is used or when software rendering is enabled. If you want to see the results to expect, select software rendering as an option. There are also some (fairly old) forum postings on this but it's really easier to try and see what you get.

I've never seen the screen capture problem with Windows, however.

[bomack]

thanks! I'll try to tweak the settings a little and see what happens.

[DrJim]

Just noticed that the location for a screen shot and some other related parameters can be set in the Edit>Preferences>Screen Grab menu.

This information is stored in a .alice file that, in Windows, is in the same directory as "My Documents" or whatever your main data folder is called.

I have no idea where this information is stored with Linux - but if it is in error (the rendering preferences are also in this file), that could be the source of your problem.

[bomack]

I don't think it's my program settings.
Finally figured out my graphics card incompletely or doesn't support 3d graphics at all.
Guess i'll try replacing that with one that supports 3d.

I'm able to get stuff done with it, it's just a bit difficult without all the features enabled. If i get a new card and it works, I'll post back here in case somebody else runs across the same issue.

thanks for your info and help, though!

[DickBaldwin]

...
Finally figured out my graphics card incompletely or doesn't support 3d graphics at all.
Guess i'll try replacing that with one that supports 3d.

...

For starters, I know next to nothing about graphics cards and barely know how to spell Linux, but I don't believe that Alice requires a graphics card that "supports 3D." I have run Alice 2.0 on a variety of XP machines, one with an expensive graphics card and most with the cheapest graphics cards available with no problems.

If I were you, I would dig a little deeper before investing in an expensive graphics card.

Dick Baldwin
Free Alice tutorials: http://www.dickbaldwin.com/tocalice.htm
Free programming tutorials: http://www.dickbaldwin.com/toc.htm

[DrJim]

Alice does off load significant processing to the graphics card. For example, running Lights05 from your lighting tutorial, http://www.alice.org/community/showthread.php?t=1045 , with hardware (DirectX 7) vs. software rendering shows significant difference in the shadow detail, as shown in the attached photo. The current version of Alice is old enough that the effects of different graphics cards may not be obvious on newer machines, at least for Windows, since even the integrated graphics capabilities in the newer machines are quite good.

However for more modern software, the graphics card can make a big difference. For cards that support DirectX 9c and on, the card will do quite excellent shading if that's also supported by the software. I don't have personal experience with DirectX 10 and Vista, but the trade press says it's even better. Note that this comment is very Microsoft specific - I have no idea what Linux might do with graphics cards.

[DickBaldwin]

Thanks for the comparison and the information about hardware rendering with Alice 2.0. That is indeed interesting, and I suspect that some of the subtle differences between the two images may have been lost in the publication process.

However, the problems described by bomack were somewhat less subtle than the differences shown by the two images.

He said "setting an objects opacity at 50% or lower also makes the object disappear instead of showing it's designated opacity.
An object's bounding window does not show up..."

That is the level of problem that I was addressing in my earlier posting about Alice 2.0 "not requiring a graphics card that "supports 3D."

Dick Baldwin
Free Alice tutorials: http://www.dickbaldwin.com/tocalice.htm
Free programming tutorials: http://www.dickbaldwin.com/toc.htm

[DrJim]

Out of curiosity, I ran a couple additional tests of "software" vs. "DirectX 7" rendering with Alice 2.0, using the attached code, and verified that software rendering alone does not eliminate opacity control. What do seem to disappear with software rendering, however, are the emissive and spectral highlight controls.

Several months ago, I discovered I do loose opacity control if I try to export to a web page. (Of course, there are other much larger problems with web page export.) Since that is dependent on Java 3D rendering, I tried that mode as well. In that mode, emissive and spectral highlight controls worked fine but opacity did not. Additionally, the screen capture button did not work (bomack's original error) and I got errors both attempting that and when I attempted to close the program - plus in at least one case the screen image was distorted when I reran the program. (I also could not obtain a screen image in this mode using shift-prt sc.)

The results shown are from my older Windows XP machine and I suspect they are both hardware and OS dependent. As a note, I did run Intel/AMD-compatible graphics cards in OpenGL mode on Unix workstations several years ago and the results were the same for both the Windows and the Unix machines, including some fairly advanced rendering options. I have no idea if such a compatibility mode is still supported in present cards, but if someone is really committed to something other than Windows, it might be worth investigating.

[DrJim]

I did a couple more tests on Java 3D rendering since my first try gave erratic results. I did successfully get a screen shot using shift>prt sc - but otherwise no difference from the first try - the opacity control and the screen capture button would not work.

The one actual rendering error I did get was corrected when I completely rebooted my machine, so I assume it is an artifact of the "memory leak" problem.

I don't have a Linux system, but I would be interesting to know if you could obtain opacity control on such a machine using Alice's software rendering option.