This project should be concidered abandoned. At the point of writing this, it should all still work but I can't provide any guarantees or support. Use at your own risk.

concider using the rigs in my more up-to-date feature set instead, which can be found here

This is a Rigify feature set to automatically create bone-chain rigs that have additional bits bobs and levers for guiding said bone-chain towards a given point or along a certain path, Inspired by Auto-Dick Rigging Tool by Likkez.

disclaimer:

I've seen some desire for people to use this and try and integrate it into existing 3rd party rigs, if this is you please read the following carefully before attempting to do so. Rigify heavily relies on the concept of metarigs, you can't simply point rigify to a rig which isn't a metarig and hope for it to work. If your intent for this is to add it onto a rig which you did not build yourself, you'll most likely be working with 2 separate rigs instead of one. If you're okay with this, read on, i'll explain how to do it somewhere below. If not, I'm sorry but there isn't much i can do about that, your best bet is probably to try and bug the original creator of the rig about integrating this feature into it.

installation

1. Download the zip
2. Navigate to Edit>Preferences>Add-ons>rigify
3. Turn it on?
4. Install feature Set from file, and select the zip file

creating the rig

The feature set fuctions like any other rigify template

1. create a bone-chain (minimum length of 3)
2. select the root of the chain in pose mode
3. Bone properties>Rigify Type>RBPNY_CUSTOM.penetrator
4. assign layers b-bone segments, etc.
5. under Object Data Properties (the green looking guy), set up some rigify bone groups and layers
6. Object Data Properties>Rigify Buttons>Generate Rig

using the rig

control groups

there are 3 different groups of bones:

1. fk-bones to animate the bone-chain
2. sheath bones that deal with the automatic targeting and guiding
3. tweak bones to adjust the final position

guidance mechanisms

the sheath bones provide 3 different mechanisms to guide the chain

• static guidance: the bone chain as a whole is rotated to intersect with a target bone (the axis looking one)
• dynamic guidance: Bones gravitate towards the guidance point based on their distance. The scale of the big sphere defines the start of this influence, and the scale of the small sphere defines when this influence is maximized.
• follow sheath the bone chain travels along a secondary set of fk bones

settings

when any of the sheath control bones are selected the n-panel will display a set of settings that influence the behavior of the above mentioned guidance mechanisms.

• static guide: defines how much the rig is influenced by the static guidance
• static target: The target for the static guidance automatically drops down the further away it is from the bone-chain root bone. This setting determines how fast it drops down
• dynamic guide: defines how much the rig is influenced by the dynamic guidance
• easing: defines how smooth the transition from getting guided through the target to following the sheath path (or going back to the original shape) is, higher values result in smoother transition but will take longer to fit the sheath guide or original shape
• offset offsets the point where the above mentioned transition takes place, negative values delay the transition to above the target point, while positive values will make the transition happen earlier.
• follow sheath defines how much the rig is influenced by the sheath bones

It helps to set up a simple looping animation and feel around with each of the settings to see how they interact.

The main target of this rig is in blender animation, the reason for this is that in order to accomplish some of the stuff above it needs to generate some helper objects of which i do not know how they behave when exporting. This was build and tested in blender 2.93 but at least for now it should (probably?) work with 2.8+

feel free to provide any kind of feedback below, and happy animating.

Integrating into 3rd party rigs

Rigify requires a metarig to work on, if you do not have a metarig, but rely on an already existing rig from somewhere else you can do the following to make this work:

1. create the penis rig
2. add a copy transforms constraint to the root bone and point it to the root bone of the other rig
3. add a child-of constraint to the fk-root bone and point it to the appropriate spine bone (don't forget to set inverse)
4. remove the parent of the fk-root bone
5. add an additional armature modifier to the mesh, check multi-modifier and define with a vertex group which armature gets control over what parts of the mesh
6. alternatively copy all of the deform bone transformations of the penis rig over to already existing deform bones via copy transform constraints

You now have integrated the penis rig into a 3rd party rig, unfortunately you now also have two rigs to manage during animation instead of one. Why can't we simply join the two rigs? you may ask. Attempting to join the two rigs has a decent chance of bricking functionality in either one of them depending on which rig will be the main rig, attempt at your own discretion.

changelog

v1.0.6

• Now backwards compatible with 2.9, no longer a reason to keep version 1.04 around
• fixed an issue preventing rig regeneration

v1.0.5

• Now compatible with blender 3.0, for those still working with blender 2.8 or 2.9, you'll have to keep using version 1.0.4
• Sheath and FK root bones are now properly rotated along with the orientation of the chain
• Locked rotation and translation channels for the dynamic guide bones to prevent potential confusion (you're only supposed to scale them)

v1.0.4

• Scaling individual tweak-bones now results in smoother transitions (Made it so that scaling tweak-bones scales the appropriate start and end point of the bbone segment when using more than 1 segment per bone)
• fixed issues arising from using non-English interfaces

v1.0.2

• fixed some spelling errors

v1.0.1

• rig now properly respects org bone parenting
• org bones follow deform bone transformations