Speed Space Rotation with Random Spin - Help

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

THREAD CLOSED
 
Thread Tools Display Modes
  06 June 2008
Speed Space Rotation with Random Spin - Help

Hi all. I'm a long time lurker here, but this is my first actual post.

I am trying to create a particle simulation in Max similar to the scenes in Hero and 300 where thousands of arrows are fired towards the camera. I've got everything working properly, except that the "arrows" are all oriented the same way. I would prefer to give them each a random spin so that the flechettes don't all line up the same way, but there doesn't seem to be an easy way to do this when using "Speed Space Follow" for rotation.

Can anyone help?
 
  06 June 2008
I would fire the arrows at an angle by turning the emitter about 45°, add a speed event with a low divergence value. Then add a gravity force. That should give each arrow a unique ballistic trajectory.

Last edited by Piflik : 06 June 2008 at 07:52 PM.
 
  06 June 2008
You could clone your arrow and do a offset rotation on each arrow, then group them and use the group as your instance. That way when the leave the emiter they already have slightly diferent rotations.
__________________
WebSite
CGPortfolio

Photos

Flickr

 
  06 June 2008
Hi guys. Thanks very much for the input. I wound up having to manually pose each projectile (it was for stills, not animation) because I was running out of time to complete the job.

Piflik - Good suggestion. That's actually similar to what I was using for a setup. Getting a unique trajectory for each projectile wasn't the problem, it was spinning each projectile by a random amount. Thanks, though!

Grury - What an inventive solution! I think that would actually have worked for me. I'll certainly keep it in mind for next time.
 
  06 June 2008
Originally Posted by Cabraswel: Hi all. I'm a long time lurker here, but this is my first actual post.

I am trying to create a particle simulation in Max similar to the scenes in Hero and 300 where thousands of arrows are fired towards the camera. I've got everything working properly, except that the "arrows" are all oriented the same way. I would prefer to give them each a random spin so that the flechettes don't all line up the same way, but there doesn't seem to be an easy way to do this when using "Speed Space Follow" for rotation.

Can anyone help?


i did a similar shot for a movie a while ago. mine pierces ice rocks in the ground...but u should be set by replacing the shape instance

the trick lays in habing a rotation set to speed space followed by a spin set to speed space follow. then u get nice gravity beding AND a nice spin...

check the stripped max9-32 file. u will need the particle flow FREEBIES to get this working. u can download them for free at orbaz.com

kind regards,
Anselm
Attached Images
File Type: gif piercing-ice.gif (46.0 KB, 38 views)
Attached Files
File Type: zip piercing-ice.zip (205.2 KB, 14 views)

Last edited by PsychoSilence : 06 June 2008 at 03:26 PM.
 
  06 June 2008
Edit: This post was NOT the way to do it

For the right way, do what others have posted or read below


-Deteled trying to use two constant evaluated Rotation Ops to solve problem to avoid confusion as it does not work.-
__________________
Proverbs 17:28 - Even a fool is counted wise when he holds his peace; When he shuts his lips, he is considered perceptive.

Last edited by charleyc : 06 June 2008 at 08:37 PM.
 
  06 June 2008
hah! we´re are heavenly connected somehow same minute same posting (content wise)
 
  06 June 2008
I am wrong here. This is what I get for posting something without trying it first. Good to hear you got a solution, but just to set people straight from my erroneous post...

The Speed Space Follow overrides any other Rotational Op (the Spin). It would appear that the best ways to do this would be as Grury says, or to set a rotation animation on your reference Geometry and use a random animation offset (if you do this, you need to apply it using an XForm modifier).
__________________
Proverbs 17:28 - Even a fool is counted wise when he holds his peace; When he shuts his lips, he is considered perceptive.
 
  06 June 2008
Originally Posted by charleyc: .

The Speed Space Follow overrides any other Rotational Op (the Spin). It would appear that the best ways to do this would be as Grury says, or to set a rotation animation on your reference Geometry and use a random animation offset (if you do this, you need to apply it using an XForm modifier).


Yep i did bang my head for a while last week and that was the quickest solution I could came up with. Gotta have a look at PsychoSilences' setup.
__________________
WebSite
CGPortfolio

Photos

Flickr

 
  06 June 2008
I want to thank everybody for all of their helpful input.

PsychoSilence & Charleyc - I, too, thought it would be a simple matter of setting Rotation to Speed Space Follow, and then adding a Spin operator afterwards. Alas, as Charleyc pointed out, they override each other, though.

My next thought was to animate the spin of the instanced object and offset it randomly in the animation, as Charleyc said, but I didn't know that it had to be done via XForm. I think that would have solved all of my troubles! Oh well, now I know for next time.

PsychoSilence, I haven't had a chance to look at your file yet. I do appreciate it, though, and I look forward to examining it later this week!
 
  06 June 2008
Originally Posted by Cabraswel: PsychoSilence, I haven't had a chance to look at your file yet. I do appreciate it, though, and I look forward to examining it later this week!


np, ur welcome

what my scene file does different then charley´s approach is that i dont use two SPIN operators but a RotationOp set to Speed Space and a SpinOp set to Speed Space follow. thats it so u get a nice down going motion with the gravity dragging the arrow down AND a spin.

kind regards,
Anselm
 
  06 June 2008
Hah! I tried the the spin+rotation op a couple of days ago and was having the same issues.

I thought I tried every possible combo to get it to work!

Seems using the Speed Space Follow last and the Rotation divergence are the keys to getting the objects to fly correctly. Cool.
__________________
poof ~>Vimeo<~
 
  06 June 2008
The Key to Anselm's approach is that Speed Space does not update continuously like Speed Space Follow. Therefore, the Spin Op will take over and do the continuous rotation. This is a very good place for Box3
__________________
Proverbs 17:28 - Even a fool is counted wise when he holds his peace; When he shuts his lips, he is considered perceptive.
 
  06 June 2008
I tried a little box#3 love, but not enough to get me there. Still waiting on this book to arrive, hoping it will help me out with box#3 a little or a lot.

LOL, a quick little screw off render...



PF Arrows QT 2.3mb
__________________
poof ~>Vimeo<~

Last edited by JohnnyRandom : 06 June 2008 at 03:32 AM. Reason: fix link
 
  06 June 2008
Hey John! Looks pretty cool. show the data view

is it really that much faster with box#3 then with the oldschool trick?
 
Thread Closed share thread



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
CGSociety
Society of Digital Artists
www.cgsociety.org

Powered by vBulletin
Copyright ©2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump
Miscellaneous

All times are GMT. The time now is 02:13 PM.


Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.