A test for a short film I hope to be making. Can I do motion tracking on Blender? Can I make it really high quality visually? Can I render in Hi-Def without my small computer dying?

I’ve been trying to create animated characters for UDK using Blender, and I discovered Darknet’s exporter, but there has not been any clear difinitive guide to setting up the blender file. So after some experimentation and trawling through forums, I finally worked it out. And so I’ve made this guide to help those that come after me…

Blender Version

I could never get the versions of Darknet’s script for Blender 2.49 to work. Luckily Blender 2.54Beta comes with the script built in. This is the version used in this guide. To make it work you have to activate it by checking the tickbox. It’s in the Addons section, Import-Export: Export Skeleton Mesh/Animation Data.

Blender armatures vs UDK armatures.

Blender bones have a top and bottom end. The top is parented to the bottom of the next bone in the chain and so on. As far as I can tell, the bones in UDK are points, and the lines that make up the ‘skeleton’ are represent the connection between each bone. What this means for us is that in Blender, if we make a chain along for instance, an arm, the last bone in the chain will not be the hand or finger- we need an extra bone on the end, the base of which will be the last point in the chain in UDK.

Strictly speaking, the bones exported to UDK represent the hierarchy, not the bones themselves.

This is how I set up my armature before IK is added.

Note: It’s important not to move or scale in Object Mode. Make sure the object centre is at 0,0,0 for both the mesh and the armature. You can scale your mesh and bones all you like in Edit Mode. I haven’t got the correct scale offhand, but I found about 250 blender units is a good height for a humanoid model to show up well in UDK.

Here follows a very simple armature design… The first bone to make is the Root. From this bone extrude a new bone, and disconnect it. This will be the Centre of Gravity (COG). It goes tip-first into the belly button and points to where the hips join. This will control the movement of his pelvis. From this extrude bones for both legs, and the spine up to the nape of the neck. From here extrude both arms and the head. Do not use the X-axis mirror function.

Be sure to include an extra bone at the tip of each chain – for instance from the end of each finger or toe, from the tips of the ears, and in my case, the tips of the jaws.

Select the mesh then shift-select the armature, then Cntrl-P to parent and choose automatic weights. You might need to touch up the vertex groups in Weight-Paint mode.

If you don’t want to use IK for your animation, you can now animate this and export it just fine.

Setting up some simple IK

Because the bones in UDK follow the links in the hierarchy of the armature, you can’t disconnect a bone, parent it to the root, and use it as an IK target as you might do normally. All the IK targets have to be external objects. The exporter also only likes the character mesh and the armature to be in the scene, and will crash if other mesh objects are present. However, it doesn’t mind objects with no vertices.

In pose mode, snap the cursor to the base of the left foot bone. In object mode, add a cube. Name it _Leftankle if you like (the _ makes sure it is at the top of the list of objects for easy finding). In pose mode, select the shin bone that points toward the foot. In the bone constraints panel, add Inverse Kinematics. The target is _Leftankle. Repeat this process for the right foot, left and right hands, and the head if you want. Don’t forget to change the chain length for each IK constraint so it reaches only to the hip or shoulder (for me the chain length is 2).

Now select each cube, and in edit mode, delete all the vertices so they become empty objects.

This is a very basic IK character setup- the angles of the hands and feet have to be controlled by rotating the bones while the positions are controlled by the target objects. You could create more targets for the tips of the hands and feet and connect them to the ankles and wrists. You could also make more targets for the knees and elbows.

Animation

You can now animate your sequence. I find it easiest to select the bones visually and use the outliner to select the IK targets.

When you’ve finished, select the mesh. If the Export Skeletal Mesh addon is activated, in the tools tab beside the 3D view will be the Unreal Tools. Choose ‘all’ and press ‘Unreal Export’. The psk (model) and PSA (animation) file will be exported to the same location and name as the Blender file you are using.

You can use the same blender scene to create another animation, save it with a different name, and use the exporter to create as many PSA files as you want your character to have actions.

In UDK.

Open the content Browser. Import the PSK file. Double click it to bring it up in the animset editor. Go File>New animset. Name it after your character. Now go File>Import PSA and select one of your animation PSA files.

You can import as many PSA animation sequences as your character has actions. I don’t know UDK well so the way I did it is to go Animsequence>Copy sequence to selected of current animset, then import another PSA, overwriting the new copy.

..and there you go!

hope that’s useful and clear enough. Reply to this post with any questions.

This is an ‘idle’ animation for games- when not doing anything else he demonstrates his character with the furtive scratching of his arse.

500×370

An orc character crafted as an experiment in normal map baking in Blender, and as a character for my students to rig and animate.

His name is Doc Fungus, and he pretends to be  doctor, running to the scene of emergency with his experimental tools close at hand.

Doc Fungus loves his fraudulent job. As he rushes to the aid of the distressed, he capers and gibbers madly.

The top model is the high res version, completely impractical for my rickety old computer. The lower two are around 2400 faces and suitable for animation on college machines and with big enough polygons for the bones to be visible through the mesh. The beginner modelling students will get the low poly version to play with, a mere 640 faces.

Designed, built and hand moulded custom Easter egg design. Intended to hark back to the roots of the egg tradition and add an earthy esoteric flavour, I combined the image of the Orphic Egg, that with a serpent wrapped around it, with the Oroboros, a serpent or dragon swallowing its own tail.

The original egg design was created in plasticine, and painted with a thick layer of latex to form a flexible mould. The whole thing was then coated in two halves of plaster, to support the shape. Then by cutting the latex in half and removing the plasticine, I could paint the inside with chocolate. I created seven eggs in total with this mould which I gave to family and friends for Easter 2009, using different combinations of dark chocolate with ginger or rose water, milk and white chocolate with chilli or almond, then covered in dried rose petals or coconut. As I used the mould it gradually degraded, losing some of the fine details.  The egg shown is an eighth, made just for pictures much later- the mould was not at its best by then.

What you can’t see is the dragon’s body with wings at the back, and the words “Light, Life, Love, Liberty” inscribed along the neck and tail. I think next year I’ll make a more substantial mould with food grade silicone and add extra detail to the egg part so I don’t necessarily have to bother with the extra coverings.

Created for the stage production of the musical “The Forbidden Planet”- the set was the inside of the space-ship with the projector screen for the cockpit window. I designed and made the monstrous manifestation of Prospero’s Id.  In this scene the beast glares in while it’s giant rubbery tentacles dangle down from the ceiling of the set to menace the actors.

The design is intended to capture the essence of wonderfully bad 1950′s scifi- the monster contains echoes of Robbie the Robot and Emperor Ming.

It’s one of my earliest animations, but I still really like it!

An experiment in designing, modelling, rigging and animating a low poly games-style character.

This is a showreel of the Spectralists sound reactive visuals we perfomed many times, at our own audio-visual night Acid Skiffle, and in London for all manner of shows. See this entry for more details.

Lots of filmclips juxtaposed in twisted ways, intersperced with my animated characters. The modelling and animation is very basic- that’s because the VJ software we used only supported animated 3DS files at the time, so no deformations or rendering of any maps besides the diffuse channel.

Oh yes, and the sound-syncing goes wrong almost immediately. Technical issues to do with rendering a sequence that isn’t live! Nonetheless I think it works rather well.