Attaching weapons and other objects to a character with custom rigs

By Sultana

This is a quick guide on how to attach items to rigs so that they move with the model. For example, weapons holding/holstering/sheathing, etc. SWTOR's skeletons and models include specific bones and naming conventions for such things, as shown in the previous guide. When using non-SWTOR armatures, no matter whether created by add-ons or manually, we have to solve this ourselves.

We do that by using a constrained Empty. The constraint allows for easy on/off toggling of attachment.

(This was something I really wanted to do when utilizing my Halo: Infinite models because I got sick and tired of having to re-posture the weapons between drawn/holstered positions)

Important

Please make sure that you have already prepared your models for use; it is best if both the character model and the item model have skeletons!

Guide

This guide was written while working on Blender 4.1.1, but it ought to be viable on previous versions of the app. Its pipeline may change with future updates, though.

1. Open Blender and have both models ready to go.

2. You will want to start by adding an Empty. This can be done by clicking the Add menu (SHIFT+A), hovering over Empty, and clicking on Plain Axes.

   

3. Next, you will want to add some constraints to the Empty you have created. Click on the Empty in your viewport or in the Outliner, then click on the Constraints icon in the contextual menu.

   1. Add an Armature constraint. This can be done by clicking Add Object Constraint. Click Add Target Bone. A new menu should come up, allowing you to select which skeleton to attach to, as well as the bone. Make sure the bone of choice is the bone you want the item to be attached to.

   2. Add a Child Of constraint. This can be done by clicking Add Object Constraint. Click Target and Bone to select which skeleton to attach to, as well as the bone. Make sure the bone of choice is the bone you want the item to be attached to. For Location, Rotation, and Scale, every box should be unchecked and grey, and there may be some times you will need to click Set Inverse. Make sure that Influence is set to 1.000.

   

4. You now need to ensure that the rig for item that is being attached currently has a Location and Rotation of 0,0,0. Click on the rig in your viewport or in the outliner, then click on the Constraints Icon in the contextual menu. You can do this by clicking the Object Properties tab and right-clicking the values and choosing Reset All to Default Values (BACKSPACE).

   

5. Finally, you are ready to attach the item's rig to the rig of the model you are looking to attach it to. Click on the rig in your viewport or in the Outliner, then click on the Constraints Icon in the context menu. Add a Child Of constraint. Click Target and choose the Empty. For Location, Rotation, and Scale, every box excluding the last row should be checked and blue, and there may be some times you will need to click Set Inverse. Make sure that Influence is set to 1.000.

   

You may now position the Empty to wherever it is you are looking to attach it to the model!

It should always move whenever that bone is moved and this will apply to both the location and rotation.

On/Off Toggle

Click on the item's rig in your viewport or in the Outliner, then click on the Constraints icon in the contextual menu. Click the eyeball icon to show/hide the constraint. Whenever you are ready to turn it back on, make sure you also reset the Location and Rotation values of the rig to 0,0,0.