Transform 0

I spent some time looking at this and it is a real problem (displaying invalid data is not good).

The issue seems to be somewhere in the range management code of the transform sliders and the way they interact with the matrix widget.

From Sankhesh: I found that loading a transforms file sets the maximum value of the transforms matrix to maximum value in the loaded file. What should be the maximum value? Is there a theoretical value that we can set?

What about setting the min and max of the range based on the value found in the file ? May be we could apply a factor to the min/max values found in the file before setting the max and min of the spinboxes.

Topic pushed to https://github.com/sankhesh/Slicer/tree/2380-Transforms-module-sliders-issue

Thanks for your fix. I've just a few comments:
a) it's odd (and not documented) that extractMinMaxTranslationValue uses the values min and max as input as well as output. I would instead initialize min/max in the function.
b) if min is 0, then the padding doesn't work. I would suggest to apply the padding ratio to (max - min) instead.
c) if the matrix translation is 0,0,0, we might still want a better default min/max other than 0,0. Maybe -200, 200 as it used to be
d) the problem is not just when selecting the node for the first time in the panel. What if the node is "selected" in the module and then the matrix values are modified externally e.g. from python/cli/...

Hi Julien,

Thanks for the comments.
a) The function is documented in the header. The min-max values are passed by reference to the function.
b) I'll change the padding to be applied to the difference between max and min.
c) The defaults are still the same(-200, 200). The patch that I added makes sure that the min-max values are changed only if the new ones are out of the current range.
d) Could you tell me how should I test this? (Once the transform file is loaded, I can get the node from the python interactor. How do I modify the matrix?)

a) Technically it is only said the values are "filled" and it is not mentioned (and it's a bit strange but it's ok, I can live with it :-) ) that the values are also "used".
d) Look at the Information for Developers section, you can write the same in python (and modify the matrix): http://www.slicer.org/slicerWiki/index.php/Documentation/4.1/Modules/Transforms

This commit replaces the pass by reference for better wrapping. I improved the documentation as well.
https://github.com/sankhesh/Slicer/commit/ba2027e5cde61aaec64f4f2d153fd338b90b809b

http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=21013
http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=21014

These commits fix the issue.

Closing resolved issues that have not been updated in more than 3 months