【转帖】meshproc edge visibility and vectorizing question
 

meshproc edge visibility and vectorizing question

meshproc edge visibility and vectorizing question
i'm currently using a vectorizer-device derived from odgigeometrysimplifier and odgsbasevectorizeview to tessellate geometries into meshes for my own engine.
my internal triangle data is constructed of indexed vertices and edges that can be "hard-edges" (visible) and interior edges.
i've got 3 questions on the processing of tessellated geometry:
1) is there a way to control the amount of tessellation when vectorizing in modelspace?
my problem here lies in the complexity of the produced entities. i've managed to control solid's tessellation via facetres-param. but this doesn't apply to other entities (some oddb3dsolids for example).
as far as i understand the problem, the tessellation is controlled by the deviation for the viewport. since i'm using a 1x1-viewport without perspective i am a little clueless how to set a appropriate deviation.
could anyone point me to the right place to manually set the deviation value?
(currently i overwrite the ::deviation function to return a user-set value which is not having any obvious effect, though.)
2) will tessellating be faster when using "rougher" approximations?
3) the visibility() in edgedata [meshproc()] is returning only 4 visibilities for 2x2 meshes. if i understood this correctly, there should be 12 meaningfull visibilities.
thanks in advance
psy

psy
# 15th may 2007, 02:28 am

softdev join date: oct 2002
location: russian federation, spb
posts: 332
hi,
1. you should choose deviation in you "1x1-viewport" coordinate system (let's say 0.01) and transform it (scale) to world coordinate system. then return obtained value from deviation() function.
2. yes
3. 2x2 mesh defines single 4-sided cell (2 vertices per each dimension).

dmitry a. novikov

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hi,
1. you should choose deviation in you "1x1-viewport" coordinate system (let's say 0.01) and transform it (scale) to world coordinate system. then return obtained value from deviation() function.
2. yes
3. 2x2 mesh defines single 4-sided cell (2 vertices per each dimension).