id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
488	Model panel view button should not enable clip planes	Tom Goddard	Eric Pettersen	"The Model Panel View button currently enables near/far clip plane as if the command ""view #2"" was issued.  This greatly impairs interactive performance for reasons that the user does not see since the clip planes often don't appear to clip anything.  What happens is once the clip planes are enabled then clipping caps are computed on every move.  That is expensive.  (If ambient shadows are enabled that can get very slow as the shadows are updated on every frame if any little part does get clipped.)  Tristan Croll ran into this and was not able to figure out why performance degraded so much.

I think when viewing a whole model the aim in the most common case is to just to center and zoom, not to clip, so the Model Panel View button should do that.

Begin forwarded message:

From: Tristan Croll
Subject: Re: Weird interaction between 3D pointer and view rotation
Date: November 29, 2016 at 12:33:50 PM PST
To: Tom Goddard 

Hi Tom,

That all makes sense, I think. One thing I'm intrigued by, though: why is there such an enormous difference in CPU use under simple lighting when standard orientation is chosen (low even after subsequently moving/rotating) vs when the view is focused on a specific model (constantly high)? Might help yield some clues to an easy-ish workaround....

T
"	enhancement	closed	major		Performance		fixed		tic20@…				all	ChimeraX