Maxscript: Update script in realtime

[Anonymous]

I wan't to keep a script active so that it always updates or when relevant to do so.

See example below, how would i autoactivate this when changing geometry,camera or viewport?

for obj in geometry do
if distance obj $camera1 > 100 then obj.segs = 6
else obj.segs = 20

/Fred

[leeminardi]

The following will change the segs of a sphere based on the distance to a camera while the timeSlider is running and the positions of the sphere and/or camera are keyframed.

fn time_p = 
(clearSelection()
	select $Camera001
pcam = $Camera001.pos
select $Sphere001
psph = $Sphere001.pos
d = length (psph - pcam)
	format "\ndis: %" d
if d < 50 then $Sphere001.segs = 32 else $Sphere001.segs = 8
) -- end select	
registerTimeCallback time_p

[Anonymous]

Yes, thank you!. This solves this LOD-problem i had,when rendering. But in a more general way, how would one make 3ds max autoupdate after changes in max, and preferable not by time as it will always run then. For animatable objects i guess you could solve it with anim. controllers but how about  the rest?

[istan · Accepted solution]

If you look for something lower level, there exists also a "registerRedrawViewsCallback"..

[Anonymous]

Yes, this is very close to what i was looking for.

Maybe there is a callback-method for when mouse and keyboard-inputs in ui is given ?.

Otherwise i think i may be able to work with "registerRedrawViewsCallback".

Thanks.

[Anonymous]

After fiddling around with registerRedrawViewsCallback i realize its pretty much interact like i wan't.

The question i get though, is there already a registerRedrawViewsCallback active in the background where i can add my script?. If every registerRedrawViewsCallback is handled like a separate process i would presume it's less taxing on the system to put all code under one callback?. Or is it too little impact to affect performance?

/noob

[istan]

I usually use this redraw callback in many of my C++ plugins for realtime drawing in the viewports. On node level I rather try to use the ReferenceMaker system - but this is very limitted for most of my applications.

[denisT.MaxDoctor]

Just letting you guys know that any registering event using registerRedrawViewsCallback or registerTimeCallback is not animatable and renderable solution. You can't render it with animation sequence!

the only way to make it renderable is to involve anyhow a controller solution - Scripted controller, Expression, Constraint or Bind controllers.

here is a snippet how it can be done using a Script controller:

delete objects

s = geosphere()
c = freecamera pos:[200,0,0] dir:x_axis

ss = s.baseobject.segs.controller = float_script()

ss.addnode #cam c
ss.addnode #obj s

scr  = ""
scr += "if isvalidnode obj and iskindof cam Camera then\n"
scr += "(\n"
scr += "	int((200 - amin (distance obj cam) 200)/40) + 1\n"
scr += ") else 4\n"

ss.setexpression scr