how to make a thin viscous fluid?

Support Animation and Rigging
#1

I am trying to make blood drip from a few characters in a word. Blood normally has a very flat surface with little to no turbulence. The problem I am having is that the fluid I am generating is too puffy. I have tried playing with the thickness of the fluid using viscosity without much luck. I have also tried playing with the gravity but this has more effect on the direction and speed opposed to the thickness. I need a thin viscous fluid.

Can anyone help?

Also, a second question, I find that the edges of my fluid tends to be very jumpy, I also can not figure out how to fix this.

I have been playing around with the settings for about 2 days now with no luck.

Here are my general settings…

Viscosity preset:
Honey

Domain gravity:
x:0
y:0.8
z:-2.2

Real world size:
1.030 metres

compressibility:
0.001

resolution:
207

Attachments

Screen shot 2010-08-31 at 6.45.17 PM.png993×507 52.3 KB


#2

fluid thickness is relative, so if you make the objects bigger in relative to the fluid then it would LOOK thinner.

That’s always been the biggest thing for me to get right.

#3

this makes sense. So perhaps if i make the “real world size” selection as low as it will go, then perhaps I could get a little closer to what I am looking for. hmmmmm…

#4

Just use the correct real world values for your sim. if your model would be typically 20cm just use 0.2.
I wouldn’t use Honey. Here are some values for blood (don’t know what they will come out like) http://blenderartists.org/forum/showthread.php?p=1631567&highlight=blood+fluid+simulation#post1631567
Other fluid values in the wiki http://wiki.blender.org/index.php/Doc:Manual/Physics/Fluids
What you should do in increase the resolution for a start, making sure your domain is only big enough to cover the volume you need so you make the most efficient use of that resolution. Add a propper blood material, add a subsurf to make a nice smooth droplet.

#5

this makes sense. So perhaps if i make the “real world size” selection as low as it will go, then perhaps I could get a little closer to what I am looking for. hmmmmm…

#6

sorry double post.

Thanks for those links, checking them out now.

#7

i have tried everything i could find to help based on your post. I also tried making the model at different scales but no matter what I do, I can’t stop the edges of liquid from quivering. I have attached 3 screen caps of 3 consecutive frames to show how much the edge of the liquid varies from frame to frame.

The only way I can see to reduce the quiver is to slow the liquid down but this only turns realtime quivering into slow motion quivering.

Is there a way to control the turbulence? I am out of ideas and time :frowning:

Attachments




#8

That is the problem with Blender’s fluid sim. I always seem to run out of time and give up as well. If you go too far away from the default parameters it just does not seem to work as described in the docs.

I view Blender’s fluid sim as kind of a “place holder” feature so the foundation can claim yeah, we got that. Other Blender features fall into that same category as well.

#9

Well I cant help but wonder if it is something I have been doing wrong because I have seen some pretty amazing samples of renders online.

I finally gave up an used a different piece of software but I will definitely give the rest of the blender particle and volume simulators a go when I have some more free time.

#10

stupid question: if you want the fluid to be locked in to a certain position, could you just apply it & that frame & leave it as is?

#11

you mean create a freeze frame effect at a particular point in the evolution of the fluid?