NoSlide

Blender Addon to prevent e.g. sliding feet

Description

This Addon integrates into the NLA-editor. Its purpose is to prevent e.g. sliding feet. The user does not need to set location or rotation keyframes for an object which should move. Distances are calculated according to the action an object is acting on in a NLA-Strip.

Therefore the addon calculates distances between e.g. an objects foot and the object center in the (user given) range of frames in which the foot should stay on the ground in the action of a NLA-Strip. The object is than moved exactly the calculated distance.

Each foot, hand or whatever will rest in a position while the object moves is called a rest member. There can be as many members as needed.

A user defined framestep-parameter determines in which framesteps the distances are calculated. There will be inserted a location (and rotation) keyframe on every framestep.

It is also possible to add rotation on each member. So the object will rotate in its movement with the e.g. foot staying on the ground in its position.

Another feature is to give a fixed distance. Like this objects can e.g. jump.

Installation

• Put the no_slide.py file into your blender addon/scripts directory.
• In blender click File > User Preferences > Addons.
• Search for NoSlide and check it.
• More info on blender addon installation, scripts directory etc. can be found here.

Usage

I will explain usage with a walk action as example.
Suppose you have a rigged character with a walk action and an NLA-strip of this action.

Preparation:

• create a vertex-group on each foot (this will be used to calculate the distance to the characters center while walking).
• select the walk NLA-strip in NLA-editor
• select the rig in 3D-View
• hit N in the NLA-editor to open settings
• at the bottom you will see NoSlide

In NoSlide:

1. enter rig-child (the character mesh/ the rigged mesh).

2. enter the NLA-strip name (here: walk)

3. choose a frame step (smaller will be more precise but more heavy to calculate)

4. add a member for each foot and name it e.g. 'left foot' and 'right foot'
   hit the + for as many feet or whatever your character has only for the extremities which stay on the ground some time

5. for each member add the corresponding vertex-group
   for left foot this would be a vertex-group with at least one vertex on the left foot

6. insert the Rest Frames:

• first rest frame for the left foot is the first frame on which the left foot rests on the ground and only the rest of the character is moving in space
• last rest frame for the left foot is the last frame on which the left foot rests on the ground and only the rest of the character is moving in space

7. give some rotation values if you like to The character will rotate with the corresponding foot on the ground. So no need for an extra 'turn right' action - but an extra strip eventually.

8. hit 'calculate distances' and have fun!