Initialising ramp attributes

[kseven]

I have created a number of ramp attributes for my node, but I get errors when the node is created because the size of the ramp array is undefined.

I initially fixed this problem by adding the entries in my AExxxTemplate script, but that only works if the user has the attribute editor open when they create the node...

To add them from the API I imagine I would need to use a plug, but I cannot create a plug in my initialize function as the my node has not yet been created.

How have other people initialised their ramps?

[60degrees]

hi kseven,
I ran into a similar problem a while back but didn't have time to fix the problem. Rob the Bloke has an example of a ramp attribute in his site: http://www.robthebloke.org/. There is also a thread in cgtalk.com that discusses this problem. I think. I hope that provides a solution for you.

Let me know how you get it to work. I will soon be making an attempt at the ramp attribute.

60*

[kseven]

I managed to fix the problem, but my solution is a but of a fudge and I imagine there must be a nicer way of doing it.

I just check the number of elements in my ramp array from the geometry function. If the value is 0, then I initialise the array to have a default value at time 0.5.

I no longer get any warnings, and it all works fine but like I say its not ideal.

I guess I just dont understand why there is no way to set the initial size of the array, and why if that is not possible the ramp attribute cannot cope with having no elements.

Anyway thanks for your help,
k7

[jade1]

I ended up overriding the postConstructor() method on my node containing the ramp, and added the default element to the ramp at that point in code. I couldn't use the MRampAttribute helper class from within postConstructor (too early for whatever reason), so had to add the default entry by manually adding data to the compound plug attribute..

[rob-bateman]

fyi, Maya7.0 contains a new ramp attribute plugin in the devkit examples..... exampleMRampAttribute.cpp

yeah, i'd suggest using the postConstructor method to initialize the ramp attr with the first 2 vars to make the AE template work.....

[60degrees]

Hi Jade,
This is a little bit of a lazy question but did you initialize the array values in the postConstructor using an MGlobal::executeCommand call?

60*

[60degrees]

Hi Rob,

"fyi, Maya7.0 contains a new ramp attribute plugin in the devkit examples..... exampleMRampAttribute.cpp"

Is the Maya7.0 devkit downloadable?

60*

[jade1]

Hey 60*, I initialised without executeCommand, something along the lines of

MPlug plugNode(thisMObject(), m_curveAttr);
MPlug defaultEntry = plugNode.elementByLogicalIndex(0); // adds the new ramp entry
// set properties of ramp entry
MPlug posPlug = defaultEntry.child(0);
posPlug.setValue(0.0f);
MPlug valPlug = defaultEntry.child(1);
valPlug.setValue(0.0f);
MPlug interpPlug = defaultEntry.child(2);
interpPlug.setValue(0);

[60degrees]

Ahh. Thank you Jade1. I was searching for an MFnAttribute function. Why do I fear MPlugs? It must be a phobia.

60*

[rob-bateman]

• Is the Maya7.0 devkit downloadable? *

The maya 7.0 beta is, but only if you are part of the beta testing program. There's some nice new stuff in there, but i suspect that they've rushed this beta out for siggraph because some of it (namely the api) seems a bit broken.

[60degrees]

Hi Rob,
how broken? broken enough to delay upgrading to 7.0? And can you divulge of any new classes or functions or are the specifics of the beta program confidential?

60*

[rob-bateman]

well, normally with maya (has been the case since version 4) the .0 releases can be a bit dodgy. Normally there's a .01 and .02 release shortly afterwards which fixes the initial bugs.

Not sure if there is any confidential thingy going on, if there is i've never signed anything....

there are some new functions sets for full body ik, and other stuff i've forgotten. Most of the stuff are small little classes to do custom swatch rendering, much better access to the HW renderer (looks like maya 8 may support DX9, just from me reading between the lines). You should be able to do post processing HW shaders now.... There are iterators for subdiv components, the cloth engine has been split into a miriad of classes which should make it a bit more flexible, there's an MPxFluidEmitter node, and i've forgotten the other stuff.

Problem is though, that in the current beta, none of it works (at all). I'm hoping it's just the beta, but i've got all my unit tests setup, so i should be able to figure out exactly how broken the final 7.0 is once i get it. The new stuff within maya itself seems more or less ok (couple of small bugs). but imo, a lot of the new stuff seems a bit gimmicky. Not happy that they've based the rigging stuff on motion builder, because tbh i think it's crap.

It's possibly the most broken beta i've ever tested, but i suspect they rushed the beta out for siggraph. So hopefully the final will be ok....

[60degrees]

Sounds cewl. I can't wait to play with the new cloth engine classes.

"Not happy that they've based the rigging stuff on motion builder, because tbh i think it's crap. "

Why?

60*