domino fall?

[-Ender]

Hard FX + Collisions.

[serge1971]

Hard FX + Collisions.
Lol. Yeah, that's what you would think, huh?! Have you tried it?? I have, but not with good results. I'm still testing though, so I might get something. It doesn't look very promising though. So if you're having good results, please post your setup.

[blaqDeaph]

Going to test it out now, but just some preliminary thoughts: you might want to make sure that the dominos are made out of more than 6 polys, as it makes for better calculation of collisions, and make sure that the dominos are 3D

[pelos]

thanks for the reply, yes i thought doing it like that i just dont know how to set it, or how to do it, i am use to lw7 and i havent try to do it in 8

any direction that i need to take?
like i need to have each piece like diferent object or has to be all in the same layer etc...

(my dominoe peices have more than just 6polys)

thanks guys!

[Hunter]

I tried it with all kinds of options on and off and hit the calculate button a gozillion times but I don't think LW Dynamics are up to it. And yes I'm using 8

[Hoopti]

This is the only "very" realistic version I've seen without manually handling them.

http://www.nextlimit.com/realflow/html/gallery/video/001.zip

Hoop

[Dennik]

Yeah, sorry to bring the bad news as well. Dominos were the first thing i tried when i got my 8.0 upgrade. And i tried and tried for 3 days. LW's dynamics have no precision. :shrug:

[pelos]

hi dennik can you upload a scene of how you try?

i am using all the pieces in one layer, as i think lw use all the point that are weld as one piece (thats why thta people need to break the obj in modeler when they whant to blow something up)

every time i hit calculete! crash!

[holyzombiejesus]

Well i tried last night for a good two hours, and came up with pretty much nothing. I managed to get one domino to fall over by itself (kinda. The bottom slid out whilst toppling, and having to use stop by stabiliser made for some weird jerky outcomes) but as soon as you put another one in the scene it goes pretty much to pot. If i were you i'd search flay for a plug-in called Impact (version 3 i think.) I really really REALLY wish it were possible in Lightwave, but i think this is currently your best bet.

Hope this helps,
HZJ

EDIT: the website for that plugin is http://www.dynamic-realities.com/impact3/ Just realised how expensive it is.
And basically to set up the basics in lightwave, you wanna get yourself a domino and a ground plane. Go to properties for the ground plane and add a collision object. Then go to the properties for the domino and add a hard fx object. Go to the properties of this and set the gravity to -9.8.
The best place to start would be to probably keyframe the domino above the ground at frame1, and let it drop to the floor. This'l help you with weight/bounce issues. For this, in the ground planes collsion properties, play around with the bounce/bind power (i usually end up lowering it to about 105....dunno if this is actually right!) and the fix value. GOOD LUCK!! :thumbsup:

[blaqDeaph]

Is there a way to assign a "weightmap" to the dominos so they have a bigger tendancy to tip over rather than move? Just a shot in the dark here

[serge1971]

Is there a way to assign a "weightmap" to the dominos so they have a bigger tendancy to tip over rather than move? Just a shot in the dark here
I don't think there's a way to change the movement in HardFX by assigning a weightmap. The only place you are able to asign a weightmap in HardFX is "Collision node", and that won't do the trick I'm afraid.

[serge1971]

Here are my results after days of testing falling dominos. :argh: :banghead: :cry:

1. Every calculation gives different results with the same setup. This is a plain BUG. This makes the domino test pretty impossible as you can imagine. When you change settings it's impossible to tell whether the changes are due to the difference in the settings, or just because every calculation is different.

2. It's necessary to stabilize the dominos after they fall. However, StopByStabilizer is useless here (also in combination with low resistance settings). The objects stop in weird poses, and don't seem to realistically react to gravity anymore.

3. HardFX (dynamics in general?) can't seem to handle 2 (or more) collisions at the same time. When a domino hits the next one, but gets hit again by the previous domino the objects are passing though eachother. (All objects in my scene have big amounts of polys, so that's not the problem.)


I believe that "falling dominos" is a pretty straight forward test for dynamics, and it should work. I'm very disappointed that there are so many different problems that make it impossible to achieve acceptable results.

[blaqDeaph]

I've been able to get the dominos to tip each other over in turn, but I still can't solve the problem of dominos falling *through* each other as they fall. Is this a bug with LW's collision or do I need to increase the number of polys in the dominos?

[Celshader]

An alternate to dynamics: Normal Displacement. Create an endomorph that has all of the dominos toppled. Then use Normal Displacement to control the domino-topple morph with a black-and-white image map.

Should work fine for long-distance shots...maybe even medium shots. Hell, maybe even for fast-moving close-ups.

---

After seeing the DStorm spinning top demo, I'm confident HardFX can handle dominos...with the right settings. Dunno the right settings off the top of my head, though.

[pelos]

mmmm
well i think i might need to do this by hand =(
i will set the pivot of each piece on the botton part (next to the side that will fall)
and then set a way with cycler so the pieces just rotate like falling.

(just came with the idea of cycler after seeing the thred with it and a demo of it)

[Skywatcher]

Well... here's a little scene that's getting in the right direction.
Not perfect but it's a start. The pieces keep moving once fallen...maybe just
fix them in the graph (after baking motion).

Just hit calculate in the dynamics tab to see the result.
Hope this helps http://www.cgtalk.com/images/icons/icon7.gifhttp://www.cgtalk.com/images/icons/icon13.gif

[HowardM]

great start Sky!
:)
why do you have multiple collisions?

[Skywatcher]

great start Sky!
:)
why do you have multiple collisions?


Well... that way I can give the floor a different friction value in diff. locations ( it helps, try changing, you'll see...)

[HowardM]

ahhh ya, i saw after i posted and started playing with the scene...
the simle solution to get rid of the shakes is to turn down the HardFX calc res to 1mm! :bounce:
takes a little longer to calc, but it works!
great job, such a simple setup, and here i was trying all these complex sims!

[blaqDeaph]

Hmmm,

I finally got it to sort of work, not by using self interaction (although that was a good idea, didnt seem to work for me). I used just clones of objects on a plane. That seems to work fine, except that the dominos bounce off each other way too much. If I choose "Stick" instead of "Bounce" for the collision type, they just fall through each other instead of sliding off.

PS. How do you post files?

[pelos]

the only progress i made, was to hit the first 2 pieces =(
the rest the fall by themself and start vibrating with the colission null (set as a plane)
i will try to up load my scene later

[serge1971]

Pelos, I managed to find a workaround, using only HardFX. It's still far from perfect but it's as close as I could get. I see I'm not able to upload a movie here, but I've posted it at Spinquad:

http://www.spinquad.com/forums/showthread.php?t=6716&page=3

Look at "dominos1.mov" (the 6th post from the top) and see if that's good enough for what you need. A few posts more down is an explanation and the scenefile. Goodluck!

[simon-s]

I may be joining this discussion quite late but I'm trying to work out this dominos problem myself.

This is what I have so far...but it only works with very few dominos. Any more and they start to fly around all over the place???? :banghead:

To create this I'm have two collision objects, one of which is set as an event. The hard fx are set to start by collision and stop by event.

This is looking pretty good but I just cant get this technique to work with more dominos.

http://www.smallanimations.co.uk/Domino_test.mov

[serge1971]

(...)
This is looking pretty good but I just cant get this technique to work with more dominos.
Yes Simon, that definitely looks good. Such a simple solution to stop the dominos. Any idea why it doesn't work with more dominos?? Do the first ones (that you've showed in your movie) stay in place though when you use more?

P.S. Let's hope that LW9 dynamics are up to a 'simple' task like this.

[simon-s]

It turns out that this technique requires the collision object to travel down the line of dominos at exactly the right speed...Too fast or too slow, and the domoinoes fly all over the place.

I have managed (through a great deal of trial and error) to get double the amount of doms to fall this time, though one or two of them do behave strangely by passing thru others.

Here is what I have so far...
next dom test (http://www.smallanimations.co.uk/Domino_test2b.mov)

[serge1971]

Here's something you might like to check. I've posted this some time ago at Spinquad. When you use "swing/spring" (rotation-tab) you can keep the dominos from sliding away (or "flying all over the place"). When you use a small amount of "swing/spring" they will fall over, but not completely. Although they'll still 'wobble' a bit, their bottom will stick to the ground, and this seems to keep them in place. Now if you would combine this with your idea to "stop by event", you might have something here.

Some others things to keep in mind (although you probably know that):
-Don't use real size dominos. They'll be far more stable when they are 1 or 2 meters tall. (Adjust the speed of the animation if they're falling too slow.)
-Assign enough 'weight' for stability (100 or 200 for example).
-Lower the 'resolution' when dominos are passing through eachother.


Personally I have given up on the "domino-issue" some time ago because I'd put far too much time into it. LW 8.x dynamics simply isn't up to the task (without the use of 'dirty' workarounds anyway). I'm gonna wait for LW 9 and try again. Goodluck to you though! :)

[simon-s]

It does seem that this domino fx thing is causing everyone real grief...I have spent the last 3 days trying to work it out and still am nowhere near to getting the results I want!

I think I may have to join you in waiting for LW 9.

Thanks for all your feedback!

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