Pref for auto-adjustment of clip planes

[olibclarke@…]

The following bug report has been submitted:
Platform:        Darwin-18.6.0-x86_64-i386-64bit
ChimeraX Version: 0.91 (2019-06-08)
Description
Hi,

Would it be possible to add a preference in the clipping section of Preferences to control auto-adjustment of near/far clipping planes? 

Currently auto-adjustment is on by default, but I prefer to have it off. It can be controlled by checkboxes in the Side View panel, but the state of these checkboxes cannot be saved. It would be good to have a preference for this - either a save button in the Side View panel, or a preference in the Clipping section of the preferences dialog.

Cheers
Oli

Log:
> camera ortho

> cofr centerOfView

> alias crosshair_on cofr centerofview showpivot true

> alias crosshair_off cofr centerofview showpivot false

> alias symclip clip near -$1 far $1 position cofr

UCSF ChimeraX version: 0.91 (2019-06-08)  
© 2016-2019 Regents of the University of California. All rights reserved.  
How to cite UCSF ChimeraX  

> ui dockable false Log

> open 1bl8 format mmCIF fromDatabase pdb

1bl8 title:  
Potassium channel (KCSA) from streptomyces lividans [more info...]  
  
Chain information for 1bl8 #1  
---  
Chain | Description  
A B C D | protein (potassium channel protein)  
  
  

> symclip 10

> symclip 5

> cofr centerOfView showPivot 5,0.3

> symclip 2

> symclip 3

> toolshed show "Side View"




OpenGL version: 4.1 INTEL-12.9.22
OpenGL renderer: Intel(R) Iris(TM) Graphics 6100
OpenGL vendor: Intel Inc.

[Tom Goddard]

Why? How would the initial position of the clip planes be established? I guess it would have to be when the first model is opened the bracket the bounding box. How is that useful versus automatic adjustment?

[olibclarke@…]

Auto-adjustment makes the center of rotation jump around in cofr centerofview mode, which is not compatible with precise centering. 

This only happens since you modified it  last week such that the cofr updates to be equidistant between the near/far clip planes.

Perhaps another solution would be to have the cofr only update in z when a clip plane has been explicitly defined? (i.e. not when it is just the bounding box)

Cheers
Oli

[olibclarke@…]

I meant to say - turning off auto adjust clip planes stops the cofr from jumping around during model rotation, and that’s what I’m doing now, hence the request for a preference along those lines.

Cheers
Oli

[Tom Goddard]

Ok, so the real problem is that center-of-view mode for the rotation center is not working well when no clip planes are shown. So I have changed center of view rotation positioning when no clip planes are enabled so that it just moves the rotation center in screen x,y to center it, not in z. Before it was using a depth equal to the center of bounding box which caused it to change depth making it hard to use.

This change makes the rotation center keep the same depth. Still the center-of-view method really is intended to be used with near/far clip planes enabled, and actually clipping something, since that is the only way to manipulate the depth of center of rotation. But it still needs to work if the user does not have clip planes on, so the above fix does that.