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ATEC 4371.001 Procedural Animation. Introduction to Procedural Methods in 3D Computer Animation Dr. Midori Kitagawa. In class. Pay attention Take notes Learn Be ready for a pop quiz. Week 2: Houdini stuff. Custom desktops Connection between nodes Houdini contexts
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ATEC 4371.001Procedural Animation Introduction to Procedural Methods in 3D Computer Animation Dr. Midori Kitagawa
In class • Pay attention • Take notes • Learn • Be ready for a pop quiz
Week 2: Houdini stuff • Custom desktops • Connection between nodes • Houdini contexts • Three functions of a node connection • Particle systems
Custom desktops • You can move your custom desktops to another machine by copying .desk fines in houdini13.0/desktop
Connection between nodes • Function of a connection between nodes differs depending on which context it is in.
Houdini contexts Major parts of Houdini (contexts) and corresponding node networks: • /ch CHOP (channel operators) network • /imgCOP (composite operators) network • /obj Objects, cameras, and lights • /obj/geo SOP (surface operators) network • /out ROP (render outputs) • /part POP (particle operators) network • /shop SHOP (shader operators) network • /vex VOP (VEX operators) network
Three functions of a node connection • Parenting (/obj only) • Passing data • Listing operations
1. Parenting • Connection works as parenting. The transformations applied to a parent node are applied to its child nodes. • Only in /obj – the scene (object) level
2. Passing date • Data are generated, modified and/or passed from an upper node to a lower node through the connection between the nodes. • In /obj/geo - the geometry (SOP) level and in other contexts
3. Listing operations • Connections are used to list operations that are applied to the nodes. • Orders are often important but not always. • A later node can affect earlier node, e.g., POP network • In /out – ROP rendering outputs and in other contexts
Particle systems • Technique for modeling and animating a class of fuzzy objects, such as fire, clouds, and water. • Particle systems model such objects as clouds of primitive particles that define their volumes. • Over a period of time, particles are: • generated into the system • moved and changed within the system • removed from the system
Particle systems • For each frame the system checks the current state of each particle and updates it for the current frame. • The state at the new frame depends on what happened in the past. • Can update itself properly only in a forward direction. • State dependent