Atom Project. <Need Dynamics Help>
 

I am building a model for an atom. I want to show the atom of a hydrogen in which electron is revolving around the nucleus. as electron revolves it leaves its short trail which dies by fading.

Here what i have done till now.

Created a nurbs circle > created a particle emitter > animation of the emitter along the nurbs circle.

:headbang:

Guys please help me in making a trail of the revolving electron which dies before the electron passes through the same point again. I want my electron to be a sphere, Glowing, fading trail, along the arc of the orbit. I dont want tangential fading tail.

I will highly appreciate your help.

Thanks

I created this quick file for you to learn from that does what you want:)

Instead of animating an emitter along the path of a circle, I simply created a sphere named "hydrogen" that rotates around a larger sphere called "Nucleus".

The small sphere rotates via a simple "time" expression applied to its' Y rotation attribute, rather than keyframing it along a path etc.

I then applied a simple surface emitter to the smaller sphere so particles would emit from it as it rotates around the larger sphere.

I then reduced the length of the "tail" by simply reducing the particle's lifespan.
So now the tail dies long before it reaches back around itself again:)

To get the tail to "fade", I leave that learning lesson up to you:)
HINT: "opacityPP" ;)

Good luck!

HipHip Huray
 

Thanks a lot. Now it perfectly makes sense. Believe me i am been dreaming all night that how to do it. I now understand the concept.

:confused: Unfortunately i am unable to take the benefit of your attachment because when i try to open it maya gives me an error

"errors have occured while reading this scene that may result in data loss. Please check the script editor for details."

Can you please recheck the file and resend me. Either here or on my email

bilalbajwa2336@hotmail.com

I highly appreciate your help. This forum is awesome. I am learning a lot.

:attn:

The file is a Maya 8.5 Unl. file.

It will not open with Maya 8 or earlier, sorry:(

I explained exactly what I did to make the file, so for you to create it yourself, it should only take you about 15-20 minutes:)

1. Select your outer, rotating, smaller sphere.
2. Goto Particles > Emit From Object.
3. Adjust the particle emitter's rate and speed to taste.
4. Adjust the ParticleShape lifespan to die quickly by setting it to a low value.

Thats pretty much it.

For more details on working with particles and emitters, please check the help under Particles and Dynamics:)

Good luck!

:attn: Thanks for reply. I am been working on it and i am able to create what i wanted (thanks to you) except there is one problem. I cant get a sharp tail of the revolving electron. Do you know how to do that?


Also tell me what are "Particle Expressions"? Is this some kind of programming??:confused:

Well, the easiest way to achieve the "sharp" shape for the tail in the way that you require, is to:

1. Select the "tail" particleShape and apply a Radial field.
2. Parent the Radial Field to the smaller sphere
3. In the Attribute Editor, set the field to be a "volume" with a shape of "Sphere".
4. Position this field at roughly the distance behind the small sphere where you want the tail to be "sharp".
5. Adjust the fields' magnitude to a NEGATIVE value (i.e. -50 for example) so as to pull the particles into the shape of a point at the moment before they die:) For more detailed explanation on that exact question, see the following chapters in the Maya help:

Using Maya
__>General
_____>Mel and Expressions
________> Particle Expressions <-- :)

Good luck!

Also, I tried exporting the scene as a .MA AND a .fbx file just in case you might be able to IMPORT that into your version of Maya.

Here is the .MA file (Maya Ascii)

....and here is the .FBX file:

And last but not least, here is a sample pic I rendered to show you the result of this quick sample scene:

Duplicating orbit problem.
 

Thanks a lot for the help. I will try what you told me. It will hopefully work.

Once i have achieved the right tail. Please tell me how to duplicate the orbit with the electron + tail. to make more orbits for a complex atom but keeping the effects same as the for the first electron. Simple duplicate option is not working.

Thanks a lot for helping me.:attn:

Yes, simple duplication does not work for some things as there are far too many connections to deal with, etc.

Since you simply need the same type of particle and emitter settings, all you need to do is get your first emitter and particleShape acting and looking the way you want, then:

1. Open the attribute editor for your emitter.
2. At the top-right of the Attribute Editor dialog window, there is a "Presets" button.
3. Click and HOLD that button to create a preset for your current emitter settings.
4. Now, select your ParticleShape and follow steps 1-3 again.

Now, all you have to do is animate any more spheres you need, then simply apply a surface emitter to them, and apply your "Preset" you created earlier by opening the attribute editor for the NEW emitters and particleShapes, and holding-down the Preset button, and choosing "Replace":)

Good luck!

Thanks a lot for your help. I will post again under this title if anything comes up.

Thanks a lot. I highly appreciate your help. :attn: :attn: :attn: :attn: :attn: :attn: :attn: :attn: :attn: :attn:

No problem:)

Animation Problem
 

Now i want to rotate my atom.

Electron is already revolving around the nucleus and i want it keep revolving while the atom rotates.

What i did was i grouped electron with nucleus. and then set key frame (360 deg) for the whole group. The problem is atom rotates fine but electrons stops revolving after one orbit.

Does my number of frames for revolving electron = total number of frames of my animation ?????

Please help me.!!!

:confused: :headbang: :(

Well, without seeing your scene file I'm not sure about your setup.

But to get everything to follow the leader, so to speak, the rule of thumb to remember in Maya parenting, is:
"Children First, Parent last".

So, if you want everything to follow the position of your nucleus, or a master group node, then select everything you wish to be children, THEN select the PARENT last, and then group it:)


To get things to rotate, say, on the Y axis WITHOUT worrying about keyframes, you can do the following:

1. Right-click on the objects Y rotation attribute in the channel box and choose "Expressions".
2. Apply the following: yourObjectRotateY = time*80;
(Sub "yourObject" for your actual object name)

If you MUST use keyframes, then you can also open the Graph Editor for your keyframed object, select the keys in the Graph editor view, and Goto: Curves, and set the Pre and Post infinity to Cycle, and your rotation will loop:)

THANKS A LOT FOR THE LAST POST. IT WAS VERY HELPFUL. But before i try it another problem came up.

Duplicating the electrons along with their attributes has driven me crazy. I am been trying constantly for over 2 hours.

The problem is how many presets do i have to set?

I managed to get through with emitter, material, etc attributes. But the radial field attributes are driving me crazy.

Can you please guide me how to deal with radial field attributes. The problem is most of the time i get an error in the help bar that nothing with that preset name exist??!!!! Moreover, i also get the same errors when i try to preset emitter. Then i thought may be i have to again do the opacitypp thingy. + i have to again create radial field + parenting it to electron sphere + its sphere volume. It definately made difference in my electron trail, but still the error prevails. I am totally lost!!!!!

Please help and guide me!!!:headbang:

Here is the file. I will be thankful to u if u take some time for my project. and tell me how to duplicate the electron orbit wit electron for other two orbits. Please guide me. Thanks a lot

Ok, after taking a look at your file, it looks like you have a LOT of things going on all at the same time such as keyframed path animation, paths with history and transforms, and there were a few other things in your file that seemed broken on my end, but that didn't hamper me at all tho:)

So, first I deleted the history and froze the transforms on your paths, and this allowed me to correctly parent your geometry+emitter to the path.

The reason I did that was to keep things simple.

That way you could get one looking and animating how you like, then, you could duplicate the whole lot and rotate it into position where you like.

But, sadly, that didn't seem to want to work without going into the Dynamic Relationship editor and relinking things and making things more difficult.

So, I had to start from scratch.

A few things to note:

When you want to Duplicate a group, but have everything be totally new objects and emitters, etc. you need to use "Duplicate Special", instead of just regular duplicate.
(See the attached image for the setting to use for that)
The jist of it is that the duplicate needs to dup the Input Connections (child nodes), and they need to be assigned NEW names, etc.

The second thing to note that when a particle emitter or particle object PRESET is made, you need to make sure NOT to include thinks like color aclum, expressions, etc as the preset for those will not be passed along to the new object. You must do those steps by hand, or via a melscript.[list=1]
So, anyhoo, how I got it to work was:
[*]I created 4 spheres[*]I positioned 3 of them on the outter areas away from the 4th, nucleus, larger sphere.[*]I repositioned the centerpoints of the outter 3 so they would rotate around the nucleus sphere each on a different axis. (rot x, y, and z)[*]I added that simple "time*90" expression to thier respective rotation channel to animate thier rotation without keyframes:)
So one sphere rotated on its X, one sphere rotated on its Y, etc..)[*]I then selected one of the smaller rotating spheres and applied a surface emitter, BUT before I did, I opened the option box and made SURE I reset it to the default settings in the dialog before I applied it.
(just to clear out anything from the previous testing)[*]Then I did the same for the other 2 spheres[*]Then I tweaked the first emitter1 and particleShape1 to look right, and made a preset for them.[*]Then I applied the preset to the remaining emitters and particleShapes, and tweaked thier look to taste.[*]Then last, I positioned the fields at the trailing end of each particle tail.[/list=1]

So, thats how I got it working for ME.
You may have issues with your setup as dynamics and keyframed path animations are not good bedfellows:(

However, all the steps above took me only 15 minutes to do, so having to start over with your animation is not always a bad thing:)

Anyhoo, good luck and I hope this helped a little to lead you on your way.

In case they help, I attached my new Maya 8.5 Unl. scene file along with a Maya .ma version as well.

Hopefully if you IMPORT the .ma file into your version of Maya it MAY give you errors, but still show the animation once you rewind it:)

PS, I stripped out all references to Maya 8.5 in the .ma file so it should at least IMPORT into most versions of Maya.

Errors may occur and there is sadly nothing I can do about that:(

Good luck!

Thanks A Lot
 

Each time you reply, each time i get amazed that your each and every thread is informative and most helpful. Thanks A Lot.

Yesterday i was feeling very upset that i can never learn Maya . But now with your last thread i have started to really learn the way to think and the way to make things easier for oneself.

I have 1 GB Ram and now my computer is killing me while running maya 7 by either giving errors like "system failed to save in temp folder" or by halting and giving me real harsh time. :angery:

But believe me Maya is running in my mind now.

I am going to try everything you told me right now. I want to ask these few off topic questions.

Whats your profession ?
where you learned maya ? And how long does it took u?
How long you are working with Maya?
What's the best way to learn it efficently?
What computer config you recommend for running maya?


I am going to try everything you told me (Thanks).
Basically i am making a cool screensaver for my desktop and also for my IPHONE. Therefore, i am going to ask you for more help when i will come to rendering part and setting my camera view.

:attn: :attn::attn: :attn: :attn: :attn: :attn:

What this error means, I usually gets it in maya then my maya closes.

basically, that means maya crashed. (yes, it crashes, just like any other program). If you go and look in the directory specifed, there may be a file that it saved when it crashed.

Re: Thanks A Lot
 

No problem, thats what the community is all about:)

My official title is Senior Effects Compositor, but mainly I work with all facets of techniques and software to complete effects shots, and I approve final shots from the Jr. artists. I actually never went to any structured school because back in 1997 when I started, there were no 3d schools, so I learned it all on my own.
(streaming video wasn't around then so it was all online text tutorials or VHS tapes from the software manufactures for everyone)
Although, in 1997 there were only about 5 tutorials TOTAL online at the time, hehe. And don't forget, Yahoo was the big thing back then, lol
I would also say that it took me about 4 straight years at home EVERY night and weekend and sometimes during the day at work learning various pieces of software and techniques. Since version 1 for Windows was released in 1998.
Before that I was using Power Animator and Dynamation. Both of those eventualy became what we now know as Maya. I was also using 3D Studio Max.
From a 2D perspective I was using Photoshop for paint and color theory training and started learning compositing in 1999 when Maya Fusion was released. On your own time and SLOWLY:) I learned that lesson the hard way years ago when I would tell myself, "I just want to make Jusrassic Park!", and then I would get frustrated and depressed and lose interest for a month or so until I found my way again. I had to learn to be patient and take things one step at a time:)
I actually explain my current rig in this thread HERE, but if you go to the Autodesk www site, they have a qualified Hardware list for you to look at and then you can make up your own mind:)

Good luck!

EXPRESSIONS
 

I am been studying about animation expressions for two days now. I think if i write an expression for one electron to revolve in an elliptical orbit then i cant animate that elliptical orbit to rotate on its axis while electron revolving around it.

What u guys think?

Please tell me how to draw trails of electrons like in this attached picture. Radial field is not giving me required result.