The following samples illustrate the usage of different features in Chaos Phoenix.
Boiling Liquid using the Particle Tuner
This scene demonstrates how to setup boiling liquid with foam, where the foam size is based on the distance to a certain object using Phoenix. The scene uses dummy non-renderable geometry to fill the teapot with liquid at the start of the simulation using the Initial Liquid Fill option.
A Liquid Source in Volume Inject mode, using nParticles as an emitter is used to stir up the liquid and create the boiling effect.
The Foam particles are enabled in the Simulator. Then in the Output rollout of the Simulator the particle Velocity, ID, Age, RGB and Size channels for the Foam are enabled.
There are 5 Particle Tuners in the scene. The first two change the color of the foam particles based on their age. The third Particle Tuner takes the red foam particles that are inside of a text object and have an age of over two seconds and makes them bigger.
The fourth Particle Tuner makes all the foam particles outside of the text object smaller. Finally the fifth Particle Tuner sets the Velocity on the Z axis for the bigger foam particles to 0 - preventing them from bouncing up and down.
Software used: Phoenix 4.40.00, V-Ray 5 hotfix 2 for Maya 2018
Shower
This scene demonstrates how to set up a simple shower scene using Phoenix. The shower nozzles are added to the Liquid source with some noise for the Outgoing Velocity in order to randomize the emission. The steps per frame are set to 10 in order to compensate for the fast moving liquid particles.
Software used: Phoenix 3.12.00, V-Ray Next, Maya 2015
Fountain
This scene demonstrates how to set up a simple fountain scene using Phoenix. There are four different sources with added noise for the Outgoing velocity in order to randomize the emission. The rendering of the Liquid simulator is disabled and the liquid particles are rendered as points using the Phoenix Particle Shader. For the ground material a Phoenix Particle Texture which uses the Wetmap particles is used as a mask to blend between a dry and wet material.
Software used: Phoenix 3.11.00, V-Ray 3.60.04, Maya 2015
Lava
This scene demonstrates how to use Phoenix's Variable Viscosity capabilities in order to simulate molten lava or metal cooling and hardening. The Phoenix Liquid Source used in the simulation emits liquid with a Viscosity value set to 1.0. Layered textures are used for the Discharge, Viscosity and RGB so that the flow has some variation.
The Particle Tuner in the scene is used to increase and randomize the viscosity of the lava over time. Real-world lava solidifies as it cools down and we want to replicate this behavior.
The shader uses a VRayBlendMaterial with VRayLight material for the hot part of the lava as the base layer and a black VRayMtl for the cold lava as the coat. The two materials are then blended with a Phoenix Grid Texture used as a mask in the Blend Material. The Grid Texture samples the Viscosity channel of the simulator so that the liquid with lower viscosity will use the hot VRayLightMaterial and the thicker liquid will use the cold VRayMtl.
Software used: Phoenix 4.10 Official Release and V-Ray Next Official Release for Maya 2018
Beach Waves
This scene demonstrates how to use the Phoenix Wave Force to create simulated waves on a shore. The simulated waves create Splash particles which in turn create Foam particles by using the Foam On Hit parameter of the Splash particles. Other important settings for the setup are the Droplets Surfing option which is enabled so that waves would slide upon the water surface instead of directly mixing with the water volume, and also the Foam Patterns which help create a more diverse surface of the foam left behind by the waves. The Foam Rising Speed is tuned to 35 cm/sec so the Foam remains underwater for a short while and can be tinted using the water material's fog color.
The Foam particles are rendered using the Phoenix Particle Shader in Point mode, which is the fastest particle render mode and is recommended for large scale scenes where individual bubbles are not visible and vast volumes of particles must be rendered. The settings are tuned in such a way that you can quickly switch to Bubble mode for the Foam and Splash mode for the Splash particles which are a bit more realistic but will take much longer to render. The Point Shadow Strength is boosted to 3.0 so the volume of the foam volume stands out and the foam is not rendered flat. The Point Alpha is lowered to 0.1 so individual foam particles don't pop up in the render as bright points, and only larger masses of foam are rendered more opaque. The Volume Light Cache of the Particle Shader is also enabled and uses a high Light Cache Speedup in order to improve the render times.
The liquid also creates WetMap particles over the shore geometry which are used to mask wet and dry materials using the Particle Texture. Mesh Smoothing is enabled in order to remove noise from the liquid mesh's surface, and the Mesh Smoothing Particle Size is increased so the mesh doesn't shrink and reveal air pockets between the liquid and the bottom which will become visible in the rendering. The preview of voxels and the Liquid and WetMap particles is switched off in order to speed up simulation and only the preview of Foam and Splash particles remains enabled. You may re-enable the preview if you want to observe the simulation process.
Software used: Phoenix 3.12.00, V-Ray 3.60.04, Maya 2015
Smoke and Fire Following a Path
This setup uses the Follow Path force in order to guide two separate simulations of smoke and fire along spline curves. The smoke simulator must exclude the fire simulator and the fire PhoenixPathFollow force. Also, the fire simulator must exclude the smoke simulator and its PhoenixPathFollow force. Thanks to this, the simulators won't interfere with each other and there won't be a specific order to simulate. Note: The Follow Path force can be used for liquids as well.
Car Tire Burnout
The tire is made Solid. Another cylindrical geometry object is created around the tire in order to drag the smoke around it. The surrounding body is made non-Solid and non-renderable. It is connected to a PHXSource and everything on the source is turned off except for Motion Velocity so that the body affects the smoke's velocity when spinning. The surrounding body must be connected to the wheel and spin together with it. The Simulator's Object voxels are set to Inscribed so that the smoke would enter the real renderable wheel's volume a bit, otherwise, there would be a visible gap between the smoke and the tire. You can control how much the smoke is dragged by the wheel using the Motion Velocity multiplier on the source.
A non-Solid, non-renderable box is placed at the contact patch between the wheel and the ground. It is connected to a second PHXSource and the source is set in Inject mode as it discharges smoke with added pressure.
The scene uses classic Vorticity for this one. PCG Symmetric conservation is used as it is more detailed than Smooth. The Conservation Quality is set to 20 so the smoke rolls better. Simulation steps are set to 2 - 1 step is not enough and the smoke starts becoming grainy due to the high velocity, but more than 2 starts to smooth out the smoke a bit too much.
Lava Lamp
Three forces are used in the scene. Two BodyForce helpers on the top and bottom of the lamp to give the fluid its vertical motion, and a Turbulence field that adds chaotic changes in the velocity field to break the bubbles apart.
The BodyForce helpers are set up such that each one affects only half the lamp. The bottom one pushes the liquid upwards, and the top one pushes it back down. After a while, the fluid loses its momentum and the system reaches equilibrium. To avoid this, a weak turbulence has been added that prevents the system from balancing and introduces additional fluid splitting forces.
A polygon grid has been added at the bottom of the lamp to help the fluid collect there, just like it does in real Lava Lamps.
The Liquid Source is in Volume Brush Emit Mode, connected to a Sphere. The "Non-Solid" option is enabled on the Sphere for the Volume Brush mode to work.
The discharge parameter is animated - if you'd rather have more/less liquid in the lamp, you can simply move the key along the timeline or input a different value for this parameter.
Play Speed is set to 0.4 to slow down the playback of the simulation.
You can play with the Random Seed value on the Turbulence node to get different looking simulations with little effort.
Morphing Liquid with Body Force
This scene shows how to shape a liquid into a geometry volume using the Body Force component.
Both Solid and non-solid modes are supported. When the object is solid, the liquid will be pushed to its surface. When the object is non-solid, the liquid would fill the object. This scene uses non-solid objects which are made non-renderable and their volume is filled. The strength of each force is animated in order to produce the morphing. The forces are activated sequentially and the liquid takes the shape of the currently active force.
Fireplace
This scene demonstrates how to set up a Fireplace simulation.
For this scene, the Conservation Method is set to Buffered as it produces the best detail for fire simulations. The Steps per Frame option is set to 5 because of the fast motion of the flames. A noise texture is used for the Outgoing Velocity and Temperature slots of the Source so that the fire emission is distributed randomly along the logs' surface which adds more diversity.
For rendering, the Fire opacity mode is set to Use Own Opacity and the render curve is adjusted to bring out the detail of the fire. The Fire opacity is multiplied by a V-Ray Distance texture in order to make the fire transparent near the logs.
Software used: Phoenix 4.40.00, V-Ray 5 hotfix 2 for Maya 2018
Ship in the Ocean
This example is a sea simulation involving foam and splash. Only the zone around the ship is simulated. The rest of the ocean is a procedural infinite surface generated by Phoenix using the Ocean Mesh Render Mode. The ocean waves over the surface are displaced at render time using the Phoenix Ocean Texture. Usually such simulations require a large container that covers the entire route of the ship. With Phoenix this is not needed. The container covers only the ship and is connected to it, and the Motion Inertia option makes the movement of the water the same as if the ship is moving in very large static container. For more information how this technique works, see the Tips and Tricks section.
The foam is born indirectly by the splash. For large scale scenes, this method is better than direct foam birth because it can't produce bunches of foam. The Foam particles' Outside Life is set to 20 sec. in order to allow the foam to leave the container and to form the wake.
Underneath the ocean surface there is a VRayPlane which is needed in order to close off the ocean volume and allow the Fog Color of the VRayMtl to work correctly and properly shade the underwater foam particles. Otherwise the open mesh of the ocean would not produce correct Fog Color. The particles are rendered as points by the Phoenix Particle Shader because bubble modes do not make sense from such camera distance and this way the rendering speed can be increased. The Ocean Subdivisions of the Phoenix Mesh are set to 6 in order to have better mesh detail and less flickering of the distant parts of the ocean mesh near the horizon. However, this would consume a significant amount of memory during rendering, so you could reduce it in case the horizon would not participate in the render sequence.
Ink in Water
This example demonstrates a technique for rendering thin smoke layers, ink in water, etc. The technique is particle-based and uses the Points Mode of the Particle Shader. The sources are set to Volume Inject emit mode and a noise map is used as a discharge map for creating this two-colored emitter. The particle shaders are being used for setting the geometry mode to points with a very small size to give a smoother look to the fluid and point color. A high value for the Light Cache Speedup option will help create quicker renders.
Nuke
This scene demonstrates how to create a highly symmetrical nuclear mushroom cloud. The setup contains a spherical emitter and source in Volume Inject emit mode connected to it which creates the fireball. The ground also has a source connected to it emitting for a couple of frames creating a "dusty" effect. The scene uses PCG Symmetric conservation with high quality in order to produce the rolling of the vortex ring that forms from the fireball, and Massive Vorticity is used in order to give more detail to the smoke.
Smoke Vortex
The content of the simulator is initialized using a box geometry with attached source to it. The source discharge mode is Volume brush which fills the whole volume inside. The geometry is not renderable and it has been made non-solid from Extra Phoenix attributes rollout menu. Then a vortex is created inside the fluid using a Maya Vortex field. Additionally, a sphere geometry object with a negative discharge is used, which pulls the smoke inside creating a hole in the middle of the vortex.
Effervescent Tablet
In this scene, the geometry of the tablet is Solid and emits Foam particles through a Liquid Source in Surface Force mode. The Emit Liquid option on the source is disabled so the liquid volume won't increase with time. The glass is filled with liquid using a ready geometry which has enabled Initial Liquid Fill enabled in its Phoenix FD Extra Attributes (check Using Initial Liquid Fill with Containers for more details on how to easily crease such geometry). The amount of born Foam particles is animated in time so that the foam is emitted only when the tablet geometry is underwater. Foam simulation is enabled in the Simulator, but the Foam Amount is set to 0, so that the Foam particles won't be born by natural conditions such as high liquid acceleration, but instead only by the source. Foam Variation Small is set to 8, while Variation Large is set to 2, so that the smallest bubbles would be much smaller than the Foam Size, while bigger bubbles would not be much larger or they would appear unnatural. The Size Distribution is set as high as 300, so that there will be a very large number of small bubbles, but not many larger ones. The Foam Half Life is set very low to 0.03 sec, so that bubbles would die as soon as they reach the surface (no matter how low the Half Life is, Foam particles would not die under water as bubbles won't look naturally if they do so). The scene uses a very low grid resolution - only 600K voxels, because the liquid does not need much detail and the main focus in on the Foam particles.
The scene is rendered in Isosurface render mode and uses the glass geometry as Render Cutter. Check Liquid Inside a Glass for more information on setting up rendering of such scenes. Isosurface Level is deliberately set below the default 0.5 - down to 0.3 - so that the liquid volume would expand and would entirely intersect the glass geometry. This way the Render Cutter would clearly cut the liquid without any remaining air pockets between the liquid and the glass. The Particle Shader has the glass mesh set as Glass Geometry so that bubbles touching the glass walls would be rendered correctly. The Bubbles Bounces option is raised to 4, so that the light scattering between the bubbles would be more realistic and the specular highlights of the bubbles would not flicker as the bubbles move.