Currently known problems and limitations

Here are some current problems and limitations of Expyriment you should be aware of. Where possible, we include suggestions on how to deal with or work around the issue.

No native 3D stimuli

Right now Expyriment only offers static 2D visual stimuli.

While PyOpenGL can be used directly to create dynamic 3D stimuli, we are planning to add a dedicated 3D stimulus class in the future, to facilitate the creation of 3D stimuli.

Inaccurate visual stimulus timing on MacOS

It appears that MacOS uses a compositor in combination with an adaptive vsync behaviour, over which Expyriment has no control. This makes it currently not possible to block on the vertical retrace, which is crucial for accurate timing (see Timing and empirical testing of Expyriment). While MacOS can still be used to create experiments, we however don’t recommend to use it for participant testing!