[vtkusers] volume rendering and progress methods

[Lisa S. Avila]

Hello Alex,

Although the volume rendering mappers do not supply progress (I don't think 
any mappers do) they do obey the abort flag. You need to set the 
AbortCheckMethod on the vtkRenderWindow. Here is an example in Tcl (taken 
from volSimple.tcl):

proc TkCheckAbort {} {
   set foo [renWin GetEventPending]
   if {$foo != 0} {renWin SetAbortRender 1}
}
renWin SetAbortCheckMethod {TkCheckAbort}


In this case the render is aborted on mouse presses. You can modify the 
logic to abort if more than a certain time elapsed (by also adding a start 
render method to start the timer)


Lisa

At 07:17 AM 6/6/2001, alext at win.tue.nl wrote:



>   Hi all,
>
>   I've got a question on volume rendering in vtk 3.1. Suppose one wants 
> to stop an
>ongoing volume rendering process, e.g. because one sees that the rendering
>takes too long and/or the results are not as expected. I thought I could use
>the interface of vtkProcessObject (inherited by e.g. the volumem mappers) to
>a) set a progress method and b) set the AbortExecutr flag in this method via
>a user interface, for example.
>
>   However, I saw that the progress method was actually not even called
>during the volume rendering! Browsing through the volume code, I couldn't
>find any occurence of the progress method being called and/or the
>AbortExecute flag being checked. Does this mean that the volume rendering
>mappers are NOT implementing the interface declared by the vtkProcessObject?
>I suspect so, since very few VTK objects really implement that interface.
>If this is so, my question to the VTK people would be: is it difficult to
>modify e.g. the vtkVolumeRayCastMapper to make it aware of the AbortExecute
>flag? Do you plan to do this in a further release?
>
>   Thanks for any hints on this,
>
>   Alex Telea
>
>-----------------------------------------------------------------
>  Dr. Alexandru C. Telea      | Technische Universiteit Eindhoven
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