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devin
12-28-2017, 06:08 PM
I'm trying to create one of your standard blood cells flowing through an artery animations. I have an emitter with instanced blood cells being driven by a wind animation path to flow along a snaking artery. I've also tossed in a low res artery collision object. I've only had partial success so I have a few questions.

How do you best go about animating a pulse for the flow? I've tried to set up a sine wave for the Wind's Power with no success.

Is it normal to have to jump over to the FX tab for the emitter and click on it in order for dynamics changes (e.g. to wind) to update?

Does scale come into play when setting up particle scenes as it does with bullet? I created the models small (~5mm vessel diameter) though not in scale with reality.

Thanks,
Devin

mummyman
12-28-2017, 06:44 PM
I've had some luck with a point cloud created in modeler. Then a morph target, plus movement with other morph targets with a bone chain. It's probably harder to explain than show. I don't have a scene at the moment saved... but here, 50 seconds in is what I've done in the past: https://www.youtube.com/watch?v=Ov1vrQ5A87U

devin
12-28-2017, 06:51 PM
Really nice and likely much better control. I'd ideally like to use the existing particle set up, if possible, but will give this a go if I can't make it work. I have a few variations on the standard flow which is another reason I'd like to stick with particles/dynamics. For instance, I have to show faster flow and more bouncing around of the cells for high blood pressure and show some clotting at some point.

I appreciate the response! I'll have to brush up again on the morph/bone chain technique.

Chrusion
12-29-2017, 07:41 AM
Is it normal to have to jump over to the FX tab for the emitter and click on it in order for dynamics changes (e.g. to wind) to update?I don't believe so. You're talking about clicking the Calculate button, right? Doing that on any object/item with an FX property will calculate the entire system of FX properties on other objects. I've been told the "Duh" thing, so don't take this as me being stupid to you, but you are clicking calculate after making changes to the Wind Power envelope. I'm wondering if wind power is the right parameter to envelope. Yes, it makes wind more or less powerful, as in more/less influential over objects, but does that change the wind's speed?

devin
12-29-2017, 07:48 AM
I don't believe so. You're talking about clicking the Calculate button, right? Doing that on any object/item with an FX property will calculate the entire system of FX properties on other objects. I've been told the "Duh" thing, so don't take this as me being stupid to you, but you are clicking calculate after making changes to the Wind Power envelope. I'm wondering if wind power is the right parameter to envelope. Yes, it makes wind more or less powerful, as in more/less influential over objects, but does that change the wind's speed?

No, I mean that if I change a parameter in another dynamics item, wind power for instance, the particles do not update until I select the emitter and then the emitter effect in the FX tab. I assume that I do not have to hit calculate after each change, right? That would be brutal.

Yes, when trying to use wind power, the setting seems to only effect the particles born at that specific time so those born at say, 5% power, will travel slowly but those born at 25% power will shoot past the slow ones and continue traveling at that speed. I've tried adding secondary wind objects to create a pulse but could not get that to work successfully either.

Thanks for the reply.

prometheus
12-29-2017, 09:22 AM
perhaps set particle weight to zero, enter itīs envelope and add an oscillator modifier for the particle weight channel...




http://forums.newtek.com/attachment.php?attachmentid=138975&d=1514564540

138975

devin
12-29-2017, 09:28 AM
perhaps set particle weight to zero, enter itīs envelope and add an oscillator modifier for the particle weight channel...


I've been testing out the spline control/morph method and getting pretty good results though I'm still trying to figure out how to incorporate some bouncing motion and possible collision. I'll give this a go as well. Thanks!

prometheus
12-29-2017, 09:32 AM
I've been testing out the spline control/morph method and getting pretty good results though I'm still trying to figure out how to incorporate some bouncing motion and possible collision. I'll give this a go as well. Thanks!

Do that..I could also upload a simple setup, where it works, but itīs a crude setup...to note, if you add the audio modifier instead of oscillator, you can actually use a heartbeat wave file for the pulse, make sure to load the audio within scene editor to have it played and heard within lightwave in sync with the animation.

devin
12-29-2017, 09:35 AM
you can actually use a heartbeat wave file for the pulse

That's super cool!

As for the setup, I'd love to take a look but only if it's not too much trouble.

prometheus
12-29-2017, 09:40 AM
That's super cool!

As for the setup, I'd love to take a look but only if it's not too much trouble.

Not really, since I just looked at the thread, created the scene within a couple of minutes, but itīs just basic particle setup, not with any dedicated blood cell items, I got one with a heartbeat as well, but you may need to reload the clip..not sure.
See attached zip.

devin
12-29-2017, 09:43 AM
Thanks, Prometheus! I really appreciate the help and insight.

prometheus
12-29-2017, 09:45 AM
sorry...I missed archiving the heartbeat scenefile..check this zipfile..