[Closed] callbacks change viewport

does this help you ?

(
	clearListener()
	
	global checkVpChange
	local curr_VP = viewport.getType()
	print ("Current VP: " + curr_VP as string)
	
	fn checkVpChange = (
		if ( (viewport.getType())!=curr_VP ) then (	-- when viewport changes
			print ("VP changed to: " + (viewport.getType()) as string)
			curr_VP = viewport.getType()
		)--end if
	)--end fn
	registerRedrawViewsCallback checkVpChange
	
	-- do stop callback :
	--unregisterRedrawViewsCallback checkVpChange
)

Thank you, Rico!

Yes, this is I need plus information about camera swap – from one camera to another

(
	clearListener()
	global checkVpChange
	local curr_VP = viewport.getType()
	 
	fn getcam =
	(	
		if curr_VP == #view_camera then
		(
			cam = try(getActiveCamera()) catch(return undefined)
			return cam	
		)
		else return undefined
	)
	local prevcam = getcam
	print ("Current VP: " + curr_VP as string)
	
	fn checkVpChange = (
		if ( (viewport.getType())!=curr_VP ) then (	-- when viewport changes
			print ("VP changed to: " + (viewport.getType()) as string)
			curr_VP = viewport.getType()
		)--end if
		else if prevcam != getcam() then print (getcam())
	)--end fn
	registerRedrawViewsCallback checkVpChange
	
	-- do stop callback :
	--unregisterRedrawViewsCallback checkVpChange
)

Please, make some corrections to my script. It’s working, but I don’t like the way I did it.

callbacks.removescripts id:#viewport_monitor
callbacks.addscript #viewportChange "format \"viewport changed > active:%\
\" viewport.activeViewport" id:#viewport_monitor

Denis, your script is looking very sweet – short and clean, but it also detects every mouse move at me. Should I use also checkVpChange() ?

probably not. the callback gives you all that you need

Just a heads up:

There is a bug in Max 2014/2015 where the viewport callback is not triggered
I reported this already, but better some aditional people report it too…

In Max 2014 and up, registering a #viewportChange callback, leads to the following, faulty behavior ( Max 2013 is fine)

• when the viewport is empty, pan/zoom and orbit trigger the callback correctly. Perspective and Ortho views alike

• as soon as anything is visible in the viewport ( type does not matter: geometry, helper, frozen or not ):

  in ortho views, Pan/Zoom completely STOP triggering the callback

  in perspective views, zooming still triggers the callback, but panning fails here too

• Panning/Zooming in a camera viewport still works

• Hidden objects do not cause this bug.

• This just appears in Max 2014 and up, Nitrous and D3D viewport a like. Max 2013 is not affected by this bug

But at me its printing

viewport changed > active: 1

in the listener many many times and very quick –
at every mouse move. – max 2012 x64