Softbody rendering

Softbody simulation and rendering are taken care of by two separate components: ObiSoftbody (simulation) and ObiSoftbodySkinner(rendering). The former simulates a particle-based softbody. The latter skins an arbitrary mesh to that particle-based representation, so that they move and deform together.

Using two separate components lets you decouple simulation and rendering, which is oftentimes very useful. Also please note that you're not forced to have a single ObiSoftbody skinner for each ObiSoftbody, you can bind multiple objects to a single softbody by using multiple ObiSoftbodySkinners.

Obi Softbody Skinner

This component automatically binds a SkinnedMeshRenderer to a softbody actor. This is done by searching for the closest particles to each mesh vertex and assigning distance-based weights, then storing this binding information in a skinmap asset.

Source softbody

The softbody to skin this object's SkinnerMeshRenderer component to.

Custom skinmap

The binding information generated by this component is stored in a skinmap asset. You can create one at Assets→Create→Obi→Skinmap, or by right clicking in a project folder and selecting Create→Obi→Skinmap. You can also click the "Create" button right next to the skinmap property, and a new skinmap will be created for you in a folder of your choice.

If no custom skinmap is used, Obi will attempt to use the skinmap information stored in the softbody's blueprint instead. In case it doesn't match the mesh currently in use by the SkinnedMeshRenderer, the mesh won't be bound at runtime and an error will be ouput to the console.

When a custom skinmap is in use, the binding options will appear in the inspector. Once you click the Bind button, Obi will bind the mesh to the softbody particles using the options you provided. Note that altering the binding options (influence, falloff, etc.) won't have any affect on the skinning results until you click "Bind".

If you re-generate the softbody blueprint but do not re-bind a custom skinmap, skinning won't work. You want to Generate the blueprint first, then Bind an object to the actor, in that order.

Softbody Influence

Global percentage of softbody influence on the skinning. A value of 0 will keep the original skinning, if any. A value of 1 will fully skin vertices to the n-closest particles within Skinning Max Distance of them. Intermediate values allow you to blend between fully animated and fully simulated skinning.

You can paint influence per-vertex using the "Paint Influence" button. In this case, the global softbody influence parameter will act as a multiplier of the per-vertex influence you paint:

Hand-painting influences on a custom skinmap.

Radius

Maximum distance to consider when skinning each vertex. Particles further away than this distance will not be considered, so usually it's a good idea to use a value large enough for all vertices in the mesh to be within this distance from their nearest particle.

Falloff

Intensity of the skinning falloff. A value of 1 means linear falloff, larger values increase falloff exponent, thus giving more weight to particles closer to the vertex.

Max influences

Maximum amount of particles that can influence a single vertex.