Hi James, I see sometimes zooming in close in orthographic projection is not possible while it works fine in perspective in the current daily build. That is a bug and I'll create a bug report. Zooming behavior has changed between Chimera 1.3 and 1.4. Here are some details that may help you. Zooming moves your view closer to a point at a certain depth in the center of the screen. What depth? In Chimera 1.3 the point to zoom in on was a hidden parameter (called "center") not shown in the Camera panel. It was set when you used the focus, window, or center commands and when you first opened a model to the center of the bounding sphere. In 1.4 I changed this to zoom in towards the center of rotation. The default location for the center of rotation also changed from 1.3 to 1.4. In 1.3 it was the center of the bounding sphere of the displayed models. In 1.4 if you are zoomed in it rotates about the closest visible object in the center of the screen and if you are zoomed out it uses the older center of bounding sphere. By "zoomed in" I mean that the bounding sphere of the displayed models is at least twice as big as the window width. The result is that in 1.4 daily builds you should zoom in on the closest visible object in the center of the window. In 1.3 you would zoom in on a point that may be in front of the closest visible object (so you could never get close) or may be behind the closest visible object (so you would collide with the object when zooming). What I've described seems to be working correctly for perspective projection (the default projection mode). Something seems slightly wrong (but not too far wrong) for orthographic projection where you can't get as close as you want. Last week I fixed a bug that may be causing your problem. It was a bug where the center of rotation point was not calculated correctly but was put in front of the closest visible object in the center. That would prevent zooming in (in both perspective and orthographic projection). It only occurred when multiple models were shown in certain spatial arrangements (a model in front had no object in center of window, but its center of bounding box was in front of closest visible object). That was fixed September 8. Tom -------- Original Message -------- Subject: [Chimera-users] Zooming and orthographic projection mode From: James Conway To: chimera-users Date: 9/11/09 12:45 PM
I am struggling a bit and would be interested in any pointers from the knowledgeable folk here. It seems that I cannot use the mouse to get arbitrarily close to a surface in orthographic mode, but I can in perspective mode. In orthographic mode (Viewing -> Camera -> Projection) if I try to zoom in, the camera instead moves in until the front surface clips, but without much actually zooming. (True for the different "Center of Rotation" methods). In the Viewing -> Side View panel, the width of the field is represented by red lines that I cannot control but which I really want to move close together.
According to the help for the Viewing -> Camera panel:
horizontal field of view (allowed range 1.0-179.0°) - how much perspective is used; does not affect the orthographic projection. The vertical field of view will change along with the horizontal field of view, but their exact relationship depends on the aspect ratio of the graphics window.
In fact, with the nightly builds of 1.4 this parameter *does* affect the orthographic projection, and does zoom in (or out) without clipping. Is there an updated explanation of how this works, and if it has changed since 1.3 as I seem to find? Am I looking in the wrong place for help on nightly builds?
Thanks,
James Conway _______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://www.cgl.ucsf.edu/mailman/listinfo/chimera-users