Take the tour ×  I'm trying to implement flowfield navigation,
as described in http://grail.cs.washington.edu/projects/crowd-
flows/ but I can't understand how the Density Function in Figure
4 of the paper is supposed to handle unit radius.  Has anyone
ever implemented that and can provide more information?  This is
the part in question:  enter image description here  Their
algorithm seems to be using only 4 cells, pointing to the lower
left of the unit, so is this some kind of kernel that needs to
be applied multiple times?   share|improve this question Could
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sharvey Mar 31 at 19:37 add comment  1 Answer  up vote 3 down
vote accepted  No, it's not a "kernel that needs to be applied
multiple times". You just apply the formulas as written, once.
It's kind of a weird rule, though, and not very clearly
described. Let me try to clarify it a bit:    • First, find the
four cells whose shared corner is closest to the unit. The unit
will contribute a non-zero