When on, this sets up muscle geometry for simulation. If tissue is connected as well, muscles and tissue will both be simulated at once, reacting to one another.

Turns on muscle end constraints. These attach muscle ends to the nearest bone. This would typically be on, you should turn this off mostly for debugging purposes.

Only create end constraints for points with a muscleendmask values above this threshold.

Determines the type of target the Muscle Ends constraint will use to constrain the Muscle Ends.

Turns on muscle-to-muscle glue constraints.

When on, allows you to specify one or more target shape(s) and their corresponding activation attribute per muscle. When activated the Otis Solver will blend the muscle rest lengths to those of the target shape.

The number of target shapes and corresponding activation attributes to specify. These are applied sequentially, but can be reordered if needed. If multiple shapes are fully active simultaneously, then only last entry on the list will be activated.

The point attribute that changes over time and controls how much the corresponding Shape Attribute is blended into the rest lengths at any given time.

A positional vector point attribute that describes the shape that the muscles should blend into as controlled by the Activation Attribute.

Turns on fascia to muscle & bone collisions. When on, muscles & bones collide with the outer surface of fascia geometry. Turning off might improve reliability in difficult scenarios with more pressure on collisions. You should still see most of the wanted effects of fascia, like to coherent muscle motion, from the muscle to tissue constraints.

Turns on rigid points that follow the input animation.

Tissue points in this group will rigidly follow the input bone animation. To use a subset of bones to drive animation, use the Bone Group parameter.

Determines the type of target to constrain the points in the Rigid Group.

Turns on tissue to bone constraints, this means constraints that cause tissue to move with bone animation. This is usually required for reasonable simulation results. The toggle serves as a debugging tool.

Bones in this group will drive muscle & tissue animation when Constrain to Nearest Bone options are used for Rigid Points Mode or Muscle Ends Mode.

Toggles the creation of tissue to muscle constraints. These are typically needed for good simulation results. The toggle exists as a debugging tool.

Turns on quality thresholds for incoming tetrahedra. Constraints created from tetrahedra that fail to match the thresholds have their stiffness values set to 0 in an attempt to stabilize simulations.

Uses the FEM Validate SOP to measure quality. Tetrahedra with quality below the threshold will not contribute to the simulation, potentially improving solver stability.

Computes volume of each tetrahedron as a fraction of mean tet volume. Tets with a fraction below the threshold will not contribute to the simulation, potentially improving solver stability.

The position attribute on muscle geometry to use while building constraints.

The position attribute on tissue geometry to use while building constraints.

The position attribute on bone geomtery to use while building constraints.

Always show the visualizations configured below, even when not entering the state of the node.

Display any bone geometry.

Display any muscle geometry.

Display any tissue geometry.

Show muscle end constraints when enabled.

The color of muscle end constraints.

Show muscle glue constraints when enabled.

The color of muscle glue constraints.

Visualize rigid points when enabled.

The color of rigid points.

Visualize tissue to bone constraints when enabled.

The color of tissue to bone constraints.

Show Tissue to Muscle Constraints when enabled.

The color of tissue to muscle constraints.

Delete any attributes not directly related to Otis simulation. You can specify additional attributes to keep using the Keep Point Attributes, Keep Vertex Attributes, Keep Primitive Attributes and Keep Detail Attributes parameters.

Additional point attributes to keep on the output geometry.

Additional vertex attributes to keep on the output geometry.

Additional primitive attributes to keep on the output geometry.

Additional detail attributes to keep on the output geometry.

Removes all groups not needed by the Otis Solver SOP.