Fluid Animation Properties

Hello everybody

This is driving me up a wall, I can’t find the active properties for the fluid sims.
The documentation says to look in the Ipo window but if I’m not mistaken that no longer exists in blender, I only switched to blender 2 months ago so I really don’t know. I tried the graph editor and NLA editor but those only seem to effect things that have already been keyframed.
I need to be a pick what frame to start the simulation at, but I can’t find anything on this anywhere. I know its there but for life of me I can’t find it.

Thanks

The fluid sim always starts from frame 1.
For inflows/outflows you can keyframe the ‘enable’ tickbox to control to stop/start of an inflow/outflow
Fluids are only baked when they are inside the domain. On frame 1 the fluid does not have to be inside the domain but you can move it there at any frame by keyframing its location.

I know it always starts at 1 and inflow outflow have the enable button. But there isn’t an active property for a fluid at all???

That’s horrible unclear in the documentation, I mean what is the whole page about Animating Fluid Properties about then, are all those properties just in the physics panel? It seems to me as if it specifically says there is a property referred to as active for fluid objects.

http://wiki.blender.org/index.php/Doc:2.6/Manual/Physics/Fluid/Animation

“The Fluid, Obstacle, Inflow, Outflow and Particle objects can use the following channels”

But your saying that if I hold the fluid outside the domain, then key frame it where I want it, when I want it in it will start at that point? But it won’t calculate it’s velocity as it just move a large distance over a single frame and shoot it all over the place?

Is this subject some sort of taboo? I’ve seen this question asked a few times, but there is never an answer.

I mean is it me just not seeing the obvious or what.

Why can’t anyone just tell me where to find those properties???

I know there out there, I am just not invited to join the secret society of people who know where to find the fluid animation properties?

The properties are on the objects that are participating in the Fluid simulation. Select your Inflow object and then activate the Physics TAB. The Fluid Type determines what properties will be displayed. For instance, you can not “enable” a Domain at a specific point. You can, however “enable” an Inflow or Outflow object at any point during the simulation.

Below you can see two animated Inflow objects in action. One sphere is static and exist inside the Domain. It’s “enabled” checkbox is animated to turn on at frame #35. The other sphere is always on but is following a path that moves it in and out of the domain. This works just as Richard initially suggests above.

Open the attached BLEND and click bake. Inspect the objects to view their properties.

Attachments


267_animated_fluid_inflow.blend (125 KB)

“I know it always starts at 1 and inflow outflow have the enable button. But there isn’t an active property for a fluid at all???” -me(previous post)

Thanks you all i really do appreciate it but I have come to the conclusion that is must be a misprint and that there is no such thing as the active property for a true fluid object.

If you want to delay the appearance of a fluid in the scene until a specific frame #, there are two ways. One is posted above. Wait until the frame number where you want the fluid to begin then either enable the inflow or move the inflow into the domain. Having said that, this can become problematic when you want the fluid to appear say 900 frames into an animation. You would have to bake 900 blank frames just to get to your starting point.

The second way is to bake the fluid simulation starting at frame #1, as typical, then use another Domain, in another scene, to read the results of that bake. When you use another Domain to read the cache from another bake, you gain the option of setting an Offset frame when that domain will start playing. Set the Offset negative to delay the Domain from starting to display the fluid.

But there isn’t an active property for a fluid at all?

So there are two ways to accomplish this.

Yes I figured all the work arounds out but in the documentation it says there is an active property for a fluid object, not an outflow or inflow, but the fluid object. It clearly isn’t in the physics panel, I was assuming it was me and this property was hiding somewhere.

I figured who wants to use a work around when you can use the proper way, but I suppose the documentation was incorrect and that this so called active property doesn’t exist for fluid objects.

Thanks for the suggestions though.

In the domain. There is a tab for offset, right next to speed in 2.67B. That tab determines when the cache is read. If you want it to say start at frame 150, put in a negative 150 after you have baked everything. Works great. It still bakes starting at frame 1 and goes as long as you initially set, but what do you care. You want it to start reading at a different frame, simply adjust the offset. This is how I have found it to work. Now if I can only get it linked into my other 100 files, I’m in business. LOL

Another tip when reading in a fluid cache is that you can indeed have multiple domains reading in cache data in the same scene. You can only have one domain generating the data, but after you have a fluid cache, multiple can be played back in one scene at the same time.

I wish smoke worked this way.

In my last project i made also 2 fluid simulations in one scene.
Watch my video here http://youtu.be/-E5JuLtE9Kg

Greets Andy