Mysterious disappearing objects (bugs in IDLgrWindow::Draw) [message #26422] |
Wed, 29 August 2001 07:07 |
m.lowry
Messages: 4 Registered: August 2001
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Junior Member |
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Hello All,
I'm new to this group but have been watching for a couple of weeks and
seen the expertise that is present here DF, CM ... So maybe somebody
cam help me out.
I've constructed an object that displays medical images acquired in
4D, ie x, y, z & time (typical dimensions 256 x 256 x 10 x 35). Onto
the display I can draw ROIs and attach them to the models. Now come
the tricky bit, the regions can be viewed on all slices in the volume
OR only on that slice on which they were drawn (slice number stored in
UVALUE of IDLgrROI). I call this 2D & 3D mode respectively and provide
a button to toggle between them. Sometimes when I do this some of the
ROIs don't get redrawn! When I interogate the graphics model hierachy
(?sp.) they are clearly in the right place but dont appear on the
screen! Are there either bugs in IDLgrWindow::Draw or am I missing
something in the transfer?
The following diagram might help:
oView
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--------------------------------------------------
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TextModel 2D_ROI_Model [array of ImageModels]
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------------ ---------- 3D_ROI_Models
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Txt Txt Txt ROI ROI ROI -----------
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ROI ROI ROI
Only 1 imagemodel is connected to the view at any one time and this
carries with it its own 3D_ROI_Model and ROIs. The trick in the 2D/3D
switch is to remove ROIs from 3D_ROI_Model and add them to
2D_ROI_Model, or vice-versa.
Q: Why do some of the ROIs disappear?
Frustratedly yours
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Martin Lowry,
Centre for Magnetic Resonance Investigations,
University of Hull,
UK
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