How Do Animations Curves Know About Time?

[katisss]

I am looking for a better way to build my nodes in maya than connecting them to the timer node.
So i started to wonder how do animations curves no about time and when to evaluate?
Can i use an animation curve and still control interpolation in my plugin?
I know it is not what it is made for but this are the requiremnts.

[rob-bateman]

QUOTE(katisss @ 05/20/08, 12:10 AM) [snapback]285856[/snapback]
I am looking for a better way to build my nodes in maya than connecting them to the timer node.

there is always a global node, time1, which controls all animation playback in the DG

QUOTE(katisss @ 05/20/08, 12:10 AM) [snapback]285856[/snapback]
So i started to wonder how do animations curves no about time and when to evaluate?

time1.outTime

QUOTE(katisss @ 05/20/08, 12:10 AM) [snapback]285856[/snapback]
Can i use an animation curve and still control interpolation in my plugin?
I know it is not what it is made for but this are the requiremnts.

yes, they are called 'set driven keys'. the normal anim curve types are

kAnimCurveTimeToAngular
kAnimCurveTimeToDistance
kAnimCurveTimeToTime
kAnimCurveTimeToUnitless

the ones you set up via set driven keys are:

kAnimCurveUnitlessToAngular
kAnimCurveUnitlessToDistance
kAnimCurveUnitlessToTime
kAnimCurveUnitlessToUnitless

[joojaa]

Also as additional info look in th api appendices, theres a number of named attributes that get connected invisibly and implied if nothing is specified.

The time to X versions have such a implicit connection.

And yes they aren't made for anaything other than letting users to do custom interpolation whatever it may be.

[katisss]

This forum is a really big help for me, thank you so much.
I will be bussy with other stuff to the end of the week but then i need to
test if our theory is correct that connecting all nodes up to the global timer kills our performance.
For 400 static spheres our filetranslator now only reaches 1 fps.

[joojaa]

QUOTE(katisss @ 05/21/08, 12:03 AM) [snapback]285923[/snapback]
test if our theory is correct that connecting all nodes up to the global timer kills our performance.

I doubt that made 10,000 connectiosn to custm timer and had no problems.

[katisss]

good to know.
Lets see on monday.
I had a look at the apendcy a. Unfortunately
I couldnt find anything related to time connection.
The driven key looks a lot like what we want. Can we use data to drive it somehow?

[katisss]

So i decided to try with setdependenciesdirty instead of affects.
This way i have control not to calculate static objects.
Are there any drawbacks to this in terms of speed and reliabilty?

[joojaa]

Chek costs time. But then again the compute of most examples is cheking if it needs update so what you do is you chek the asker and see if the value is ik first and return if it is.

[katisss]

So we do a lot better/faster in "transform only" animation and with static objects by using the setDependencydirty to decide whether to compute or not in each frame.
Mesh animation continues to be slow but it s a good start.

[joojaa]

I still dont reallly understand what is so slow.

So could you racap how do you define slow. And how much data it is pushing. as SLOW is a term thets undefined in genral. (for example you might think something is sslow even if i think its fast.)

QUOTE
So we do a lot better/faster in "transform only" animation and with static objects by using the setDependencydirty to decide whether to compute or not in each frame.
Mesh animation continues to be slow but it s a good start.

Well i would do it in compute anyway.

[katisss]

i prefer to do in compute but it seems to be a problem.
Even when everything was commented in compute except for the setplugclean.

What is slow:
We have custom nodes for both mesh data and animation data,
both are read from a custom file format.
The file format library knows if an update is required and was asked about that
in the compute. Otherwise we just set plugClean.
So i dont have the information if something is "static" when it is first build.

One of the problems i suppose is that translate, rotate, scale and shear are handled separately
(and compute is callesd 4 times when time changes).
I didnt design the plugin so i have to go with what is there.
A mesh update is a complete redraw of the mesh including UV data and some per face blind data.

What surprises me is that not calling compute is some 20 times faster than calling compute and doing nothing there . I wish there was a way to see what maya really does.

[joojaa]

Well im actually interested in how much data you push. And what kind of performance is slow.

Amnd what kind fo performance do you get with the simplest api examples.

QUOTE
What surprises me is that not calling compute is some 20 times faster than calling compute and doing nothing there . I wish there was a way to see what maya really does.

well thats kind of the idea. But doing nothing meands whjat exactly, doing really nothing in compute will cause maya to time out.

[katisss]

In the compute we just call to the library to ask whether to update or not.
For testing i set the result to not update always which is a possible result.

[joojaa]

Well again yoru not answering my questtion.

I am asking how much data are you pushing and how fast exactly is slow. 1 ms per pop or 2000ms per pop. This will give me some measure of what you mean by slow. So i know if its worth doing anything. Or wether ior not your posibly choking yoru problem at some other stage.

[katisss]

1 fps playback with 400 static spheres is slow.
How do you mean how much data?
Its transform and geometry data.

[joojaa]

How many polys are the spheres and how do you drive them (again a sphere is no measure of speed because it does not tell anything). Is it all one mesh or several meshes or are the spheres locator's etc.. are they all handled by one node?

[katisss]

its 400 faces each and the animation is controlled by a custom node.
Which in case of a static object is not of objects.

[joojaa]

So basically you have one mesh thet has 400 faces 400 times? resulting in a 160,000 face mesh, but again no measure of the data amount as a face can be as many sided as possible. So at minimum means somewhere around half a million points operations per update. So we are talking at about 10-50 million floating points operations a second?

In general if possible you dont want to push everything in one mesh set becase this would cause all points t update but rether push them as 400 individual nodes because its has a huge potential for speedup.

So dont try to design monolithic nodes try to design flexible ones.

[katisss]

I didnt design any of it.
I ask for the time in the compute with a data handle.
The time drives all the transforms and the mesh.
Maybe this makes it do too much work.

[joojaa]

QUOTE
I didnt design any of it.

Well now you need to clearly redesign EVERYTHING form scratch. thet the only way you can fix bad design.

QUOTE(katisss @ 05/28/08, 02:46 PM) [snapback]286330[/snapback]
I ask for the time in the compute with a data handle.

Well as long as its coming form the data block its fine

Anway it stands to reason if you do

anytrigger -> update everything

is going to be a bad solution. Now if you carry along everything in one data entry its going to be slow because it has no option but to update them all on change.