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Captain Chaos
08-17-2015, 11:46 AM
Trying to make a bowl of candy based on the William Vaughn cereal bowl tutorial. In mine the candy pieces are consistently going through the bowl with some getting stuck inside the mesh. What did I do wrong?

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Snosrap
08-17-2015, 01:24 PM
Use Bullet - not Hard FX.

Captain Chaos
08-17-2015, 01:49 PM
Use Bullet - not Hard FX.

Thanks for replying.

I guess that's a third party thing? I'll go get it, but I'm still curious about why it worked for him and not me.

prometheus
08-17-2015, 01:54 PM
Use Bullet - not Hard FX.

if bullet isnīt available and if you just want to learn hard fx...before going bullet.

maybe raise your collision radius slightly..and perhaps set roughness to 100, hard to say since I havent used hardfx for a while, and I donīt see the etc tab on your image.
it could also help to divide your object a bit more, and set that bowl object type to advanced object not object.
- - - Updated - - -


Thanks for replying.

I guess that's a third party thing? I'll go get it, but I'm still curious about why it worked for him and not me.

No bullet is native for lightwave ..but depends on what version of lightwave you have.

speismonqui
08-17-2015, 01:58 PM
different settings maybe? I remember that video tutorial, he used a different type of bowl IIRC. Those small things can chance the overall effect so you won't get the exact same results as his.

Like Snosrap said above, use bullet dynamics (not a plugin, lightwave native since 11? I think?), results are much better and faster than old HardFx.

Captain Chaos
08-17-2015, 02:05 PM
Sorry, I just saw that bullet is available to me. I've never used it because I rarely do animation. Even this is for a static image. I'll dig up some bullet tutorials.
Thanks, guys.

prometheus
08-17-2015, 02:10 PM
Bullet is located in layout under the fx tab, if you have later lightwave versions, you have the bullet on off button, item properties which will open up the bullet menu settings, but you can get started quick and easy, by selecting each item..then check the bowl to be static, and balls to be parts bodies, it they are on one layer ..you wont see it take effect until you click the play button..it calculates with that button..and enter item or world properties to see and change settings.


https://www.youtube.com/watch?v=aefrZJcVESk

Ztreem
08-17-2015, 03:02 PM
This is very easy to setup with bullet. I would have done it this way.
1. Load bowl and candy object in layout.
2. Select bowl and make it a static body.
3. Select candy and make it a rigid body.
4. Open item properties ( bullet menu) and set the collision shape of both items to convex hull.
5. Place candy in the middle of the bowl floating in the air above the bowl. ( not to far up)
6. Clone candy object( ctrl+c) and set the number of clones to around 200 or as many you think you need to fill the bowl.
7. Hit play and watch the simulation. Tweak settings if needed. Done!

Snosrap
08-17-2015, 05:24 PM
I'll dig up some bullet tutorials.
Hardly necessary, as it is drop dead stupid simple. Ztreem pretty much nail the tut for you. :)

DCjr
08-18-2015, 12:28 AM
Hardly necessary, as it is drop dead stupid simple. Ztreem pretty much nail the tut for you. :)

What the fah!

prometheus
08-18-2015, 06:14 AM
thereīs always the issue of jittering, thereīs been threads about that around here, and recommendations to use layers for each segment, so using one single object layer with arrayed candy balls, might be troublesome as they do not rest properly but continously jitters.

though I am not sure it will be completly jitterfree even with multilayered or cloned objects.

Captain Chaos
08-18-2015, 12:25 PM
I couldn't find "Convex hull" but I saw "convex pieces" and picked that. Is it the same thing? In any case, it didn't work. I got this:

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prometheus
08-18-2015, 12:52 PM
I couldn't find "Convex hull" but I saw "convex pieces" and picked that. Is it the same thing? In any case, it didn't work. I got this:

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that was probably written wrong...I am sure he ment convex pieces, that is correct anyway.

think you might need raise the collision margin a bit, make sure you have selected all your candy pieces in the bullet list, and change to convex pieces, the bowl ..static.

Ztreem
08-18-2015, 02:19 PM
I couldn't find "Convex hull" but I saw "convex pieces" and picked that. Is it the same thing? In any case, it didn't work. I got this:

129319

I wrote the steps from the top of my head, so I only remember that it was something with convex...
If the candy pieces is spherical you can choose sphere instead of convex.

You can also increase the fps ( I think its called that) number in the world tab to prevent the pieces from going through the bowl. Calculation time will go up.

Ztreem
08-18-2015, 02:24 PM
think you might need raise the collision margin a bit

Just remember with too much margin the pieces will not touch each other and it will look unrealistic. I always keep it at zero, I don't like when pieces are not touching the ground etc.

prometheus
08-18-2015, 02:35 PM
I wrote the steps from the top of my head, so I only remember that it was something with convex...
If the candy pieces is spherical you can choose sphere instead of convex.

You can also increase the fps ( I think its called that) number in the world tab to prevent the pieces from going through the bowl. Calculation time will go up.

yup..dynamics frame rate...default 180 I think..and it might need to be set much higher.


Just remember with too much margin the pieces will not touch each other and it will look unrealistic. I always keep it at zero, I don't like when pieces are not touching the ground etc.

that I know and that is of course true..but you shouldnīt be revealing all that ..itīs so much fun letting people grind their brains..and thus developing some more neurons :)

Snosrap
08-18-2015, 02:50 PM
I couldn't find "Convex hull" but I saw "convex pieces" and picked that. Is it the same thing? In any case, it didn't work. I got this:

129319 Make sure you have enough segments in the bowl so the candy won't fall through. The more points the better the dynamic simulation. Also dynamics is one area where modeling to scale can cause problems. Scale up your objects and things might work better, you can always bake out the sim and rescale it down to size.

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MonroePoteet
08-18-2015, 11:12 PM
Here's another thread on a similar (same?) topic:

http://forums.newtek.com/showthread.php?146368-Particle-object-emitter-and-bullet-dynamics&p=1428110&viewfull=1#post1428110

where I posted a classic FX scene filling a bowl with "M&M" type candies. It's not Bullet, though.

Good luck!

mTp

Captain Chaos
08-19-2015, 10:56 AM
Make sure you have enough segments in the bowl so the candy won't fall through. The more points the better the dynamic simulation. Also dynamics is one area where modeling to scale can cause problems. Scale up your objects and things might work better, you can always bake out the sim and rescale it down to size.

129321

Odd, I was having trouble with them going through but didn't notice any difference with more polys. I even tried freezing it with no noticeable change.

Captain Chaos
08-19-2015, 11:12 AM
So here's what I came up with, which I would call fair. When I positioned the candies close together, the group exploded and they went all over the place. To get enough of them spaced far enough apart I made a giant cone for the collision object to catch and funnel all the candies into the bowl. I have the candy's collision margins set to 1mm, but the pieces are still overlapping each other. I had to set the cone's margin to 3mm to keep the candy from going through it.

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The glass effect looks like crap, but that's a separate issue.

Snosrap
08-19-2015, 11:27 AM
To get enough of them spaced far enough apart I made a giant cone for the collision object to catch and funnel all the candies into the bowl. Now you're thinking. :)

Captain Chaos
08-19-2015, 11:54 AM
Now you're thinking. :)

Thanks. Any thoughts on the candies crashing into each other?

Ztreem
08-19-2015, 01:53 PM
Thanks. Any thoughts on the candies crashing into each other?

Have you tested to increase the dynamic frame rate to something like 500-1500? What scale is the scene? Bullet works best if things is around 1 meter in size. I tried doing a simulation once of a small thing in milimeter size and it didn't work at all. I had to scale it up for the simulation, then save it and then scale it down again for render.