Cineversity

I have a recurring issue when using emitters with dynamics. No matter what my settings in the dynamics tab a few and sometimes hundreds of emitted particles escape from inside my collide object.

I set the collide objects to static mesh. The particles are low poly spheres. The attached images display my dynamic settings. I have tried numerous settings and the result is always the same.

Any ideas?  Thank you in advance.

Hi Devoted,

Is it possible to use a sphere instead of your model and leave a particle emitter in the scene. In that way we have a simplified model to see what happen.

I assume, as you mentioned that this bugs you since a longer time, that you have had that not only with this model. Which means it won’t be a mesh/polygon problem.

You might check that with the support, where you can have a more secure data exchange (I assume you do not like to have your model online)

Is there any chance that you increase the Margin value in the Dynamic Tag? See attachment, let it run and take a look how different the particles behave after frame 90.

All the best

Sassi

Thanks for the info. I never really considered the margin. The problem is if I have a “tube” or in this case a nerve that is 2cm and I want a .5 cm particle to be contained inside it I really can’t increase the margin. If I increase the margin it won’t fit in the tube.

However I guess it’s ok if they escape the nerves as long as they stay inside the body mesh, the blur on the surface distorts the accuracy anyway. I have increased the margin on the body and am caching my dynamics now. We will see.

Is it always best to convert hypernurb objects to mesh before using dynamics? In general should I convert all objects to mesh before dynamics? I noticed in your example everything is converted.

One last issue I am having. I added wind but I don’t want the wind to affect all the emitters. I click the emitter and add the wind to the “exclude” input but when I look in the “include” it appears there also. It is adding the wind to the include and exclude.  Basically I can’t get the wind to effect only certain emitters. It effects them all. Am I doing something wrong?

Thank you!

Now that I have been thinking maybe I should not use an emitter for the nerve tubes. I could use the splines I created to model the nerves, assign the glowing object via a cloner to the spline, and add an effector to provide a little turbulence to the glowing objects.

I think it would work, what do you think?

Thanks

HI Devoted,

The HyperNURBS can stay in the way they are, it should not affect the Dynamic calculation. But you might make a test, as everything in C4D is based on combinations, and the number of possible combinations is practically endless. If someone would claim to know every possible situation, I would just leave him alone. ;o)

If the margin would limit the space of the object-movement too much, perhaps a larger object is needed. Note that what you “see” (or render) is not necessarily the object that needs to be used for effect. Just to introduce an option here.

The main question that I got during this thread is, is dynamics used here to get things fast done and is it really needed. Wouldn’t be a more controlled, and perhaps faster way a better idea? Sometimes particles along a spline might work even better, as you gain much more control. Just a thought.

I have not found a single rule, that would fix all problems which are introduced by the mixture of the individual scenes. The only thing that I found true for anything, is that time of the scene, and movement of the objects are not monitored seamlessly. It is done in steps. If these steps are too large for a given scene adjustments are needed. In close connection to that is the idea when the “system” triggers a collision.

The default parameter deliver over a long time a good starting point. But of course—as it is a dynamic system—the initial situation might change rapidly. Exactly there is a (at least for me) a discussion on the current set up needed. As I can’t say from some parameters if it works or not, it is a little bit more complex than that. Not that I have for each situation an answer, but sometimes a single parameter left at default or set wrongly might change the result to an unwanted product.

All the best

Sassi

P.S. funny our posts have crossed. Yes, I’m certain Splines might give you a more controllable scene.

Yeah, I don’t know why I didn’t think about it yesterday! It’s what I should have been doing for the nerves all along.

I think you may have missed this question from previous post.
One last issue I am having. I added wind but I don’t want the wind to affect all the emitters. I click the emitter and add the wind to the “exclude” input but when I look in the “include” it appears there also. It is adding the wind to the include and exclude.  Basically I can’t get the wind to effect only certain emitters. It effects them all. Am I doing something wrong?

Dr. Sassi I cant thank you enough.

You’re welcome.

I did not missed that, but yes I haven’t answered, as I liked to have a scene file and I would have fixed it then ;o)

If you use the “Standard Particle Emitter”, please go to the tab “Include” and drag all “Wind” objects in it that you like to have excluded. Set the pull down menu to excluded.

In the “Dynamic Tag”, it is called “Forces” (just to confuse everyone ;o) but works in a with the same result here, drag the “Wind” object into the list, set it as well to exclude and you’re ready to go.

Have a great weekend
Sassi