Visual Effects 2: Houdini Fluids

Here is the flipbook and render of my Houdini Fluids assignment for Visual Effects 2. For this assignment, we were allowed to do whatever simulation we wanted, as long as it was something we had not done before. Because I still don't know much about Houdini, I decided to stick with that program, trying out the Fluids side instead of the Pyro. I chose to running water from a sink because I knew that Fluids have to have millions of particles in order for the water to look correct. This way, I could still try water but keep my computer from blowing up. I was surprised at how fast water actually runs out of a faucets. I suppose that I had just never really paid too much attention before. Still, I think that my simulation may run slightly fast. Other then that, I am fairly happy with out it turned out.

Below, you can see the plan that I wrote up before starting the simulation.

           For this assignment, I will be simulating water running from a sink faucet. To start off, I will model a simple sink in Maya. The sink will include the bowl, the faucet itself, handles, and a raised stopper. Once this is done, I will import these assets into Houdini as one mesh. I know that I want the fluids to hit the sink and bounce off, just like they would in the real world, so I will select the sink mesh and turn it into a Static Object under the Rigid Bodies tab

            To start the fluid simulation, I will create a sphere to emit from, and then under the Particle Fluids tab, select Emit Particles to create the fluid Flip Tank. This sphere will be placed under the faucet opening.  To adjust the flip tank size and shape, I will go into the flipsolver and change the Box Shape numbers. To change the position, I will adjust the Box Center I will size this to fit only the area that I need – from the faucet to the base of the sink. Next, I will go inside the AutoDop Network in order to adjust the motion. Before adjusting any motion, though, I must first change the Visualization of the fluid to Particles inside the flipfluidobject. Once that is done, I will lower the Particle Separation to create a more detailed and interesting splash. If I find that the splash is not going quite as fast as I want, then I will raise the gravity of the fluid.

            Once I have the motion looking nice, I will then move onto the shading of the water. The first thing that I must do is set up a light. If a light is not projected onto the fluid, then I will have a hard time adjusting the settings for an accurate portrayal of water. To do this, I will create a simple Directional Light and aim it towards the sink. Once this is done, I will adjust the shader by turning the Cloud Density to 0 in the uniformvolume node. This is because the fluid I am making is transparent water, not a type of smoke. After that, I will move onto the color. Inside the basic liquid node, under the Diffuse tab, I will adjust the Base Color to be a slightly less overpowering blue. Also, I will make sure that the Color in the Reflection tab is lighter than the Base Color. Once that is done, I will make sure that the Index of Refraction under Settings is set to that of water – 1.33.

            After I have all of the motion working correctly and the shading matches that of water, then I can render out my sequence and create a Flipbook of my simulation.

Here is the simple sink prop that I modeled for the scene.