# Why do keyframed objects cause fluid baking to slow down so much?

In the following figures we show the results of our attempts in order to mix a key-framed animation with a fluid simulation. As you can see, in the top one the obstacle is static (fix) but in the bottom one it turns counterclockwise slowly.

The Static one took only 5 minutes to be baked, however, the dynamic one took 65 minutes on the same computer system!?

We need to know:
1. First, whether this massive time difference is usual even though there is no significant difference between the two simulation?
2. Is there any tip / trick to speed-up the baking of mixed animation/simulations?

Our final simulation (for education purpose, btw) will be much more complex in terms of dynamic and the number of objects in it.

• Did you enable Export Animated Mesh? – gandalf3 Dec 22 '13 at 22:24
• @gandalf3 No we didn't. Should we? For the two simulation everything is exactly the same except in the dynamic one we have used key-frames to rotate the obstacle. – Developer Dec 23 '13 at 2:51
• @Developer Not need do it. Thats is for calculate animations with parents, objects with armatures and so on. – gabrign Jan 28 '14 at 1:37
• @Developer I was wondering because enabling it will drastically slow down the simulation, so I thought it was a possible cause. – gandalf3 Jan 28 '14 at 3:14