Surface Methods for Creating Triangulations

 

These methods rely on equally or similarly named methods on Chain, TimeStep and Geom2d and their superclasses, they call them for the current frame or time or on all frames of the model. The project Refine provides an interface which allows to access most of these methods interactively, see section 8.2.8.

     

SURFACE * surface

Call "refine-send"/"coarsen" send on the model geometry for the current time * time. Methods used are Chain "refine"/"coarsen"(which just pass on the method to their object and next_scene), TimeStep "refine"/"coarsen" (7.3.3) and the refine/coarsen methods on Adapt2d described in section 6.3.3.4.

   GRAPE(surface, "refine-all-send")()

SURFACE * surface

Refine all frames in the model geometry using the same refine-field which is taken from the inter object and copied to all steps.

Using this method can be dangerous since all steps must have the same connectivity. If a method like "refine-send" or "equiangulate-send" which changes the connectivity locally (for some of the frames) was called before "refine-all-send" will result in an error, the model might be unusable. Another danger is that Adapt2d "refine-local-send" might use correction steps resulting in neighbour frames with different connectivities, in this case interpolation between these frames is no longer possible.

     

SURFACE * surface
char * mollify_method

"mollify" on Triangd or Geom2d improves the quality of the triangulation by replacing all points by the average of the point itself and its neighbours.

These two methods provide an interface to apply "mollify" to the surface model geometry: "mollify-send" calls "mollify" with "mollify-send" as argument, "mollify" then applies the method given as argument to the model. If "mollify-send" is used as a display method it allows to change several parameter, e.g. the number of times the mollify_method should be called and whether the mollify operation should be applied to boundary points, too.

Using two methods just to call one other might seem a bit strange but it allows to implement other mollify operation for subclasses of Surface, in this case only the "mollify-send" method which calls "mollify" with a different method as argument has to be implemented.

   GRAPE(surface, "equiangulate-send")()

SURFACE * surface

This method just calls "equiangulate" on the model for the current * time. "equiangulate" on Chain just passes on the arguments, TimeStep "equiangulate" handles the connectivity (e.g. splitting pre_object and post_object if necessary). The methods which are finally called are "equiangulate-send" on Geom2d (6.3.4.5) and Triang2d (6.3.1.4).