Model panel view button should not enable clip planes

[Tom Goddard]

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

[Eric Pettersen]

So what's the command equivalent of what the View button should do?

--Eric

[goddard@…]

How about command "view #1 clip false"?  But you would have to add the "clip" option to view to use that.

[Eric Pettersen]

So you're saying there's currently no exact command equivalent to what you're requesting (could be multiple commands)? The only option is to enhance an existing command?

--Eric

[goddard@…]

I think the view command is the only current command that centers and zooms and it currently does not have any option to control clipping.  Possibly needed operation could be done via Python calls instead — but adding an option to the view command should be very easy (15 minutes work).  If you like I can add that option.

[Eric Pettersen]

Well, as part of the change I wanted to have all the Model Panel buttons log command equivalents. Whenever I get to this I can add the option (assuming it hasn't magically appeared before I get to it). I may have to muck with other commands as well in order to do the other buttons.

--Eric

[Tom Goddard]

The view command now has a "clip true|false" option.

[Eric Pettersen]

Okay, "View" no longer turns on clipping. Also, model panel buttons log the equivalent commands.

--Eric