Hi, and welcome to a tutorial for Softimage XSI 4.2. Bear in mind that this is not a modeling tutorial, nor a lesson in using XSI Cloth. It is more of a look at how to use the fluid dynamic particles for your own setups and use obstacles.
Make sure your scene objects have their own surfaces when you do this tutorial. That is extremely important so you can separate them. Sometimes the fluid shader will not work on the first try, so save your scene, close XSI, and restart your scene. The particles should appear as fluids.
First, let us create a fluid emitter. Make sure you are in the "Simulate” bar (4 is the keyboard shortcut) and go to Create>Particles>Fluid>Disc
Now a window with the parameters will pop up. We will focus on the speed of the emission and life span of the particles (marked in the red box....). And move the disc up so you can see it.
If you play your simulation, you will see the particles falling down and clipping through your object(s), but do not worry about that. If you have got this far, you are doing excellent. Now you can change the speed to as fast as you want but keep your Max Life to 5 for performance. Your playback should look like above.
Setting up the obstacles
This part is of great importance, because you can have as many obstacles as you want interacting with the particles. So now let us set up these obstacles…. In my scene I will add a NURBS sphere, but you can use whatever objects you have available. I have a gravity force in my scene, you will need one too…to do that go to Get>Force>Gravity. And leave the parameters at the default. Then to Modify>Environment>Apply Forces. And your mouse Icon should change to "pick”, select your gravity force. And right click on the mouse to end the selection. Your particle cloud should have gravity influence
Now we will set up our obstacles. Select your cloud particles and go to environment tab and select "Set Obstacles”. You can choose whatever obstacles you have. And a box will pop up, and change the collision settings to Actual Shape. And lower the elasticity so the particles do not bounce too much. If you are still in playback scrub the timeline so XSI can recalculate. Here is a grab from my scene. If your particles collide with the objects, you are in good shape