Controlling Fluid Simulations with Custom Fields in Houdini Master ...

Figure 14: The preset smoke solver with the color eld added to it, as describedin (5.3.1)5.3 Examples of custom eldsThe next sections will talk about how some setups can be created and what isrequired to implement the custom elds in dops for each example.5.3.1 Colour eld additionOnce the colour (Cd) attribute is transferred onto a volume in SOPS using thevolume attribute transfer tool, the necessary elds can be added in DOPS, thenode tree can be seen in Figure (14) :1. A Sop Vector Field, Cd, is dened to bring in the newly dened Cd eldfrom SOPS. This eld will contain the color information throughout thesimulation.2. Another Sop Vector Field, Cd_source, is dened using the Cd eld fromSOPS. This eld will be used to add color information to the Cd eld atthe beginning of every frame. If this eld is animated, it is required thatthe Time and SOP Path are always evaluated. The Time parametershould be set to $T.3. Using a Gas Calculate with a the calculation set to Maximum, the destinationeld set to Cd and the source eld set to Cd_source will copyinformation from the source into the destination eld at the start of everyframe using a maximum operation.4. Advect the color eld by the velocity, using a Gas Advect microsolvers25