Fluid Particle tutorial
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.
Side note: 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.Â 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.Â 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. Â 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
Now comes the shader part of the tutorial...and it does involve the render tree and render region, so open up the render tree (7 key on the keyboard) with the particle cloud selected. You will see this node branch. Update if necessary.
Now this branch is already set up for us, we need to tweak the parameters for the blobs and change nodes. I am going to be making water here, but you can make whatever you like. The steps will be the same. In the render tree, select node>surface>and more. You want the ParticleFluidV2. Also get a volume node: Nodes>Volume>More, and find the Particle_vol_fluidV2. It may be in your system folder. Take your time. Your tree should look like this.
Now we will tweak the shader. Still in your render tree double click the green node and a box will appear with parameters. Keep your render region open to see the results update...use my settings.
And if you did all of that, you have successfully created a particle fluid simulation to use in your scenes. Sure my scene is a crude example, but you can make your own particles. If you have questions about the tutorial, please ask... Thank you