Issues noticed by Nyall from reviewing code

[ccrook]

You'll get a lot of crashes, because there's other parts of your
renderer which need upgrading to QGIS 3.0 API. And unfortunately when
a renderer crashes in Python code, it segfaults after dumping the
python error to the console. You'll need to run in a console to see
the Python errors which are thrown and upgrade the corresponding API
calls.

Also - I noticed you access a layer from the project within your
startRender method -- is is very unsafe for a renderer to do, since it
is running in a background thread and should not be accessing layers
at all. Just another thing to try to refactor out as you upgrade your
plugin for 3.0!

[rfsleal]

@ccrook, is there a fully functional version of the plugin for Qgis3.x? I couldn't find any versions above 3.6.2 in the official repository. That one doesn't work with the newer qgis3 LTR (https://plugins.qgis.org/plugins/VectorFieldRenderer/version/3.6.2/).
Thanks!

[ccrook]

@rfsleal Hi. Unfortunately not yet. I've not had time to work on it .. had hoped to do so over Christmas period but didn't work out. There are some large challenges in it and at the moment I'm looking at using a different approach using the existing rendering capablities in QGIS. QGIS rendering is much more sophisticated than when I built the vector field renderer. It won't give such a tidy user interface, but will probably be much more maintainable, and probably more efficient for rendering. Sorry I can't give you a more helpful response at this stage..