API Changes


Woo keeps track of current API version in woo.master.api, which is set from the internal woo.apiversion module.

Every script should state the API it was programmed for by setting woo.master.usesApi:

woo.master.usesApi=10177 # or (1,1,77) which is converted 10000*1+100*1+77

If usesApi is smaller than api, functions which changed their behavior in significant ways (other than fixing bugs) will issue a warning about possibly unexpected result. In that case, this page can be consulted to find out about was to update the code accordingly.


This page keeps track of major (and some minor) API changes for the purposes of updating the code and also for warning when older API is being used, possibly with different results.

API 10104


This API change was commited Oct 3, 2017

API 10103


This API change was commited Oct 23, 2015.

  • Remove woo.dem.Bo1_Sphere_Aabb.distFactor, woo.dem.Cg2_Sphere_Sphere_L6Geom.distFactor, woo.dem.Grid1_Sphere.distFactor; accessing thsoe from Python (reading or writing) will raise ValueError immediately. These values were replaced by DemField.distFactor, which is read from affected functors directly. This change ensures consistency of distFactor accross all functors and makes it easier to change everywhere.

    A related change is that woo.models.ContactModelSelector.distFactor is not set automatically in engines returned from woo.dem.DemField.minimalEngines; this must be set by hand in woo.dem.DemField.distFactor. A warning will be issued when API is smaller than 10103 and distFactor is set.

API 10102


This API change was commited Aug 5, 2015.

  • All “static” classes (i.e. classes with static attributes declared with WOO_CLASS_BASE_DOC_STATICATTRS and similar) were converted to regular classes with per-instance attributes. It was done for architectural reasons and cleaner interfaces (e.g. saving rendering options along with the simulation). Some backwards-incompatible changes had to be introduced:

    • woo.dem.Tracer must be instantiated as any other engine, and multiple independent instances may exist. Since Tracer was mostly used from the UI (where the internals were adjusted), there are no issues expected.

    • All rendering classes and functors (woo.gl.Renderer, woo.gl.Gl1_DemField and all others) were converted to regular classes. Instances of rendering classes are contained in woo.gl.GlSetup attached to S.gl. S.gl is automatically created (with defaults) on-demand if not assigned explicitly. woo.gl.GlSetup can be instantiated with arbitrary OpenGL functors passed as argument (shown below), and functors are accessed as in S.gl.cPhys (for woo.gl.Gl1_CPhys: leading Gl1 removed and capital converted to lowercase). S.gl also defines the __call__ operator, which accepts any GL functor instances, which will replace the ones already existing.

    • Assigning static attributes will not report any error, but will not do what you expect:

      try: # try-block for running in headless mode
         import woo.gl
         woo.gl.Renderer.scaleOn=True  # creates new class attribute scaleOn, no effect on rendering
      except ImportError: pass
      # TODO: show the exception being raised

      and should be replaced with

      1. setup of the whole rendering through GlSetup from scratch:

           import woo.gl
        except ImportError: pass
      2. replacing only some functors and keeping the rest of GlSetup intact:

      3. keeping everything (functors and GlSetup) and only change individual parameters:

    • Construction (which used to result in assignment of static attributes) will have no effect, as the object will be immediately discarded:


      and should be again replaced by using GlSetup:

      ## or
    • Warning will be issued when Renderer or any GL functor is construted with arguments (such as Gl1_Sphere(quality=4), but not for Gl1_Sphere()).

  • Scene.any, which used to be a list of arbitrary objects was removed; it was mostly used for storing OpenGL renderers with the simulation (which is no longer necessary) and is functionally superseded by labeled objects in S.lab. Since Scene.any was only sparsely documented, it was removed directly and an exception will be raised when accessed.

API 10101


This API change was commited Jul 28, 2015.

  • woo.dem.ParticleContainer.add (as in S.dem.par.add newly may add nodes of particles to S.dem.nodes, depending on the optional argument nodes, which is -1 by default. The default (-1) will add the node if it has mass, or prescribed velocity, angular velocity, or imposition; 0 will not add nodes, 1 will add all nodes. If any node is in S.dem.nodes, it is silently skipped.

    This change makes woo.dem.DemField.collectNodes largely obsolete, since nodes from particles are collected at the time they are added.

    When script uses an older API, warning is issued for every use of woo.dem.DemField.collectNodes.

  • Introduced API versioning


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