Mechanical Characters: Rigging and Animating for video games

Hello BA,

I am starting a thread in the hopes that it will help solve some of the problems I have encountered while developing my mechanical character for my video game as well as provide resources for others looking to add mechanical character to their games.

Here are the steps I have taken thus far:

  • modeled individual meshes for each part all contained within one blender file.
  • built a rig and weighted each mesh to each appropriate bone
  • animated idle walk and jump cycles
  • set up game logic

Here are the problems have been having:

  • multiple animations won’t save in one .blend (this prevents exporting the animations in one file)
  • when in the game engine only one part follows the animation

I have attached the .blend of where I am at as I am in need of help. I have followed the simple game character tutorials and searched for resources detailing mechanical game character creation and found only examples of rigging a simple arm.

With your help I aim to solve this workflow and post a tutorial for others to follow. Thanks in advance for your time.


Watt_GLtest_jump.blend (1.62 MB)

Hey everyone I’m back after a short break from 3D stuff.

The above problem remains an issue.

In rigging mechanical tutorials all the object are independent? But in every game model I have seen they are one mesh. Please help. I need a resource for building a robot for game use.

[CTRL J] is the solution to all your problems. Select all the parts, the last one must be preferably in the center, like the big cylinder of the body. [CTRL J] and… Boom! You have a single mesh. I think it would be wise to make sure scale and rotation are applied. If you really want to, you can also set the origin of all the parts at the same position before to join but it makes no difference.

I just tested with your file. The animation is still working after I joined the mesh. Still, I would recommend to do it before to weight paint because it seems really weird to me. (I was actually surprised it just worked.) :wink:

killer kalurra thanks. Will give it a go. Any suggestions for weight painting mechanical meshes? Since i can’t select the individual parts as objects any more. This would be most helpful.

Mechanical game character workflow (WIP) Please corrct me if I am wrong
this part for others seeking to rig mechanical game characters.

  1. model your character using individual objects.
  2. select all parts with the most central part selected las [CTRL J]
  3. build armature
  4. parent (mesh = child of armature)
  5. weight paint (this seems like the trick part to me)

BTW i was able to get things to work with out joining the object into one mesh. here is the file.
Watt_GLtest_2.blend (1.66 MB)
I think there may be some issues yet. all of the rigid objects are parented directly to bones ie body bulb key etc…
the arms and legs however… because some of them are soft i weight painted them. these are parented to the to the rig as object(arms) and armature (legs) i didnt think it would work this way either. but it seems to.

NM i found a great resource for weight painting mechanical

Watt_GLtest_3_singlemesh.blend (1.8 MB)

Here is the updated v and the steps i took to fix it.

  1. I joined all the meshes into one. [ctrl j]
  2. made the armature a parent of the mesh (with empty groups) select mesh then armature [ctrl p]
  3. assigned parts of the mesh to relevant bones (found a nice trick for this)

*tip for assigning vertices to bones

  1. put both mesh and armature into object mode
  2. change armature to pose mode [ctrl tab]
  3. select the mesh (while in pose mode) [right click]
  4. enter weight paint mode [ctrl tab]
  5. [tab] into edit mode and bones remain selectable
  6. select vertices [L] usually gets the whole group if you mesh is good. [shift+alt+right click] was also help full.

there are some settings that caused me issue. in one tutorial i found it said the parent relationship of the mesh should be set to the armature as an armature with no modifier applied… this did not work however.

I left it parented to the armature as an object and left the armature modifier (object set to armature).

Now Set up the logic bricks in the game logic.

Watt walks fine now.

still have trouble with getting the other anims to play as they should.
I want key spin to run always and idle to run only when not walking.

You rig is coming along fine. I don’t quite get what you are tying to do with upper leg setup; lots of bones. Also robot foot is not quite deforming properly, especially toes.