By SideFX

This scene file shows how a shoulder can be muscled with the new Muscle tool in Houdini 8.1 which is currently in Public Beta. This scene will be updated later with a version that shows the character's skin being deformed by the muscles.

This is a digital asset character of a human skeleton that is rigged to simulate accurate skeletal motion. At joints such as the knee, the thigh bone geometry rolls over the calf bone with the underlying kinematics adjusting to allow for this realistic motion. The rib cage is designed to maintain its volume and the clavicle, shoulder blades and even the knee caps have realist motion built in. The animator can also apply offsets to this automated motion in cases where they want a particular effect.

The arms and legs make good use of FK/IK blending with the arms capable of being controlled by either a world space end effector or a local end effector. There is also a special reverse arm rig that runs from the elbow up through the clavicle. This lets the animator lock down the elbow then move the body. These techniques are covered by some how-to lesson available in the asset's help.

This human skeleton is the first stage in the generation of a realistic human that will eventually include bone and muscle deformations. The goal is to derive the character's skin from the bone, muscle geometry using inflate. Keep an eye out in the exchange for an updated versions of this skeleton with muscles. For now, have fun animating and posing this skeleton and testing out the rigging concepts used in its creation. When updated versions are available then any animation to put on this defintion of the skeleton will be transferable to the muscled skeleton.

Refer to the asset's help card for for information on how-to use the rig.

This dynamic simulation of a smoke bomb integrates Houdini's Rigid Body and Voxel Fluid Dynamics. The smoke is emitted using information from the bomb canister to make sure that it emits in the desired direction while the canister spins through the air. The look of the smoke is derived from the material-based noise which sticks to the smoke as it moves. The final look is also enhanced with per-voxel motion blur.

One interesting thing to note in this simulation, that was not used in the video released on the main page, is the creation of an extra "color" volume which can be used to emit color in the smoke. Both videos are included in the attached file. This should help provide incite into how the volume tools work in Houdini.

Note that there is commenting on all nodes found in the file, and that some values have been changed from the video that was posted earlier, and this attached file to provide a more responsive experience. These changes will be made apparent in the commenting.

How it works:

* An rigid body simulation takes place causing the canister to fall and spin.

* We use the orientation of the canister to control the initial velocity of the fluid smoke

* Takes are used in this file for easy render passes.

* One thing that is important to note, is that lights that are lighting volumes must have motion blurred shadows turned off to correctly render motion blurred volumes.

This digital asset lets you visualize any attribute that exists in a geometry (SOP) chain. Simply input the attribute name and choose which type of attribute it is to visualize. The purpose of this utility is to give you visual feedback at any point in your geometry (SOP) network.

Refer to the asset's help card for a quick how to use asset.

This is a directory containing a html based dynamics FAQ along with sample files to help answer each of the questions. Eventually these will be part of the Houdini docs but for now they are available here.

Note: this is an update to an earlier version of the FAQ. This update includes text answers to all of the questions and a couple of broken links have been fixed.