Making a fluid system shoot up before flowing down

I’m trying to make a volcano animation, and I want to use a fluid system to make lava come out and run down the sides. I know a little bit about using fluid systems, but all I know how to do is have the fluid run down. How can I make the fluid shoot up first and then run down the volcano?

In the fluid properties set an initial velocity in the +Z direction.


this is to start an object (blob) of fluid moving up. You may also want to try an inflow object

I tried setting the initial velocity in the z direction, but all that happened was things fell into the volcano. I don’t know how to use inflow (I looked all over for a tutorial, but none were helpful). Does anyone know what I’m doing wrong? (Thanks for trying to help)

A crude low resolution example of a fluid inflow.
fluid.blend (107 KB)


Never mind, I figured out inflow and I made it work. Thanks for your help!

LOL I just made a little vid on this for you, oh well.

For anyone lurking - fluid inflow is a 3D object. The volume of the object dictates how much fluid flows per second. The velocity can be animated using a fluid sim ipo so you can animate Z vector from 1-4 and back and make a spurt of lava straight up into the air.

Fluid inflow has a reported bug. If the inflow object is too far down inside a depression of a solid object it won’t work. SO if you inflow stops then move it up out of the hole! One trick is to make your obstacle (eg water pitcher or hose nozzle) out of a sheet or spun curve. Then you can bury the inflow inside it BUT there are some problems with collision and occaisionally the fluid will leak through the walls.

You can put the inflow in another layer and not render that layer so fluid will seemingly flood in from thin air.

here is an example:

Edit also attached is the blend file you can play with (2.49b)


fluidtest_06.blend (315 KB)