Frequently-asked Questions

General Issues

Q: Is Steamshovel’s documentation up-to-date?

A: Yes! Documentation is important and we try hard to keep it in order. If you find an error, please try to fix it yourself if you can (assuming it is a minor thing), otherwise please submit a software ticket.

Q: I would like to make vector graphics with Steamshovel. How do I do it?

A: We use OpenGL to render the 3D graphics. OpenGL can only produce raster graphics, so it is not possible for Steamshovel to generate vector graphics without changing fundamentally how Steamshovel works.

Startup Issues

Warnings

Q: I see the following warning on program startup:

WARN (steamshovel): Cannot embed IPython Qt widget, falling back to tty-based console [...]

Should I be concerned?

A: This warning occurs when you don’t have the necessary dependencies for the in-program ipython console, which appears as part of the steamshovel graphic user interface. If you are content to interact with python in your console, then you can ignore this warning. The graphical console requires several of IPython’s optional dependencies to be installed, most notably PyQt. On OSX, the easiest way to install PyQt is through homebrew.

Q: I see the following warning on program startup:

GLShaderProgram: could not create shader program
ERROR (steamshovel): Could not prepare shader (SceneObject.cpp:360 in QGLShaderProgram* setupShader(QString, QString))
WARN (steamshovel): Cannot use glshovel.frag shader; it will use the fallback renderer. (SceneObject.cpp:374 in static void ShaderManager::setupSphereShader(QString, bool&))

Should I be concerned?

A: Warnings like this occur when your system thinks it can handle programmable graphics shaders, but then has problems compiling them. Errors like this are graphics-driver dependent, and may be more common under X forwarding. The best way to avoid graphics problems is to run steamshovel locally (i.e. not over X) and keep your system’s graphic drivers up to date. That said, these warnings can be ignored; however, steamshovel’s graphical output may be of a lower quality.

Runtime Issues

Q: I sometimes see the following repeated warning when I switch frames:

QVariantMap DBusMenuExporterDBus::getProperties(int, const QStringList&) const: Condition failed: action

Should I be concerned?

A: It seems safe to ignore this warning. It was investigated, but eventually the investigation was dropped since the warning does not seem to indicate faulty behavior. Others are welcome to try to fix this. The pattern of occurance points to either a race condition between Python code that runs out of sync with Qt code or between different events inside the Qt event loop. It seems to occur mainly when frames are switched in quick succession.

Q: I tried to create a movie file, but I got the following error from ffmpeg:

*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
Unrecognized option 'nostdin'

A: Update your copy of ffmpeg. For the historical drama, see the dicussion on StackOverflow.