Disabling Viewport Redraw

[ajohnson]

I'm coming from using the 3ds Max API, which has functions that allow viewport redraw to be disabled/enabled. This can be useful if some code is performing operations that are computationally expensive to draw, or you don't want the user to see some operations that are being performed. Is there a way to do this using the Maya API (or MEL, if necessary)? I've looked over the docs, but nothing has popped out at me.

Thanks much,

Andrew

[joojaa]

Sure, theres a option for this, atleast in mel but i supect alos in teh api.

But thing is theres probably no need to draw stuff on screen anyways, all that is doable and fetchable can be done between refresh cycles in one go. So if your doing soem stepping trough a animation for example THEN FOR gods sake dont go and change time, just read the data from the source offline. Since all the keyframes values are available for reading without any hitch.

But yeah i usualy disable refresh while i bake doefrmations because it speeds maya up by HEAPS.

[rob-bateman]

do you mean currentTime -u, or do you know a better way of doing it? (just out of curiosity)

In the API, disabling refresh is not really available (afaik). You can ask attributes to be evaulated in a different context (ie, at a specific time), which has a similar effect.

I personally step through the anims, i know you can get the animation keys seperately, however for reliable extraction of bone data, anim curves tend to cause problems unless you correctly handle all other dependencies (IK, expressions with setAttr in them, constraints, driven keys etc).

[ajohnson]

QUOTE(Joojaa @ 05/12/06, 12:58 AM) [snapback]237025[/snapback]
Sure, theres a option for this, atleast in mel but i supect alos in teh api.

Would you mind sharing what that option is? As I said, I've looked, but haven't been able to find it.

In my case, by the way, I'm not needing to change/animate things over time. I'm simply performing a set of mixed API / MEL calls that need to happen in a certain order and I don't want the results of these commands to be displayed in the viewports. If i could, i'd string them all together to run in a single MEL script (thus ensuring that redraw is disabled for the duration), but that is not possible in this case because it's a set of mixed MEL / API calls, so I need to be able to disable redraw at the beginning of the sequence of commands and enable it again once the commands are finished.

Thanks.

[joojaa]

yes you could use different contexts. Anyway in maya its pointless to ask not to redraw bacuas may redraws nothing unless told to do so.

QUOTE(AndyJ @ 05/13/06, 09:21 AM) [snapback]237122[/snapback]
but that is not possible in this case because it's a set of mixed MEL / API calls.

I dont undrstand this statement, as it makes absolutely no sense. Thing is if your doing mixed api/mel calls you need to call them form somewhere right. And bacuse theres no other way to itegrate this than making mel commands out of your api calls you can expose them inside one proc! If you cant then somethg wierd indeed is going on wich you probably shouldnt meddle with in firstplace.

Even if the commends were to come form a external source you can still loop it inside a mel proc. Your proc might be a infinite loop that waits whatever it is your doing to finish by polling one commend continiously.

CurrentTime -u wont work but following example will! Note current time itself implies a refresh unfortunately. se below how to fix that.

CODE
for ($i=0;$i<10000;$i++){
setAttr "time1.outTime" $i;
print `getAttr "nurbsSphere1.translateX"`;
}
//note this is WAY fatser using current time!
//4 secs versus 142 secs to be exact.

N

[rob-bateman]

Joojaa, you are a god! thanks for that. I never thought to try something as simple, and frankly obvious. Previously i just restricted my exporters are stuff to animating the scene once, and caching the data. This should help me speed things up a fair amount. I owe you a beer. In the api it's a little bit more involved doing this....

CODE
            float _time_ = 1.0f; // set this value to the time you want
            MTime currTime( _time_ ,MTime::uiUnit());
            MSelectionList sl;
            MGlobal::selectByName("time1",MGlobal::kReplaceList);
            MGlobal::getActiveSelectionList(sl);
            MObject oTime;
            sl.getDependNode(0,oTime);
            MFnDependencyNode fnTime( oTime );
            MPlug plug = fnTime.findPlug("outTime");
            plug.setValue(currTime);