[vtkusers] BUG in vtkClipPolyData (?)

[Sebastien BARRE]

Hi

A long time ago I had a discussion with Bill (or Will) regarding how to 
perform polygonal capping, and he drives me to :
graphics/examplesTcl/capCow.tcl

I played with that example. Then a couple of month ago I played with that 
example again, and it was so sloooooooooooow. But still usable, thus I did 
not worry about that.

I checked my own code where vtkClipPolyData is used on datasets comprising 
200 000 points or more.
It was *no more* usable, it was so slow that nothing could be done 
interactively.

I looked at my code, I checked the examples, and here it is :
	if you use GetClippedOutput and GetOutput in the same renderer (displaying 
both the cut and remaining parts), then the vtkClipPolyData filter is 
updated nearly on each redraw :(( It is therefore impossible to move one or 
both parts, as the filter keep updating again and again.

Open capCow.tcl or clipSphCyl.tcl and add :
clipper SetStartMethod { puts "started" }

Surprise... :)


I check the CVS and noticed :
Revision : 1.20
Date : 1999/3/19 20:12:0
Author : 'lorensen'
State : 'Exp'
Lines : +4 -3
Description :
ERR: was re-executing every time if GetClippedOutput was applied. Added 
Update method.

Bill, are you sure it has been fixed ?

Thanks
-- 
Sebastien BARRE
IRCOM-SIC, UMR-CNRS 6615 - Université de Poitiers
Bât. SP2MI, Bvd 3 - Téléport 2, BP 179 F-86960 Futuroscope Cedex
Tel. : +33 (0)5 49 49 65 92, Fax : +33 (0)5 49 49 65 70
http://www-sic.univ-poitiers.fr/barre/ ou  http://www.hds.utc.fr/~barre/