Fixing and using Bioloid Mesh files

[limor]

If you want to create a Bioloid robot and have a 3D visual of the robot when playing with MotionEditor you need to know the naming convention of the bone structure that is used by Robotis software.

You can easily deduct the bone structure naming convention by looking at the bone hierarchy through a tool like Fragmotion (fragmotion.com) that can read .X directx mesh files.

You may also want to use the 3D model of one of the Bioloid robots with 3Dstudio/Maya to render some cool animation or physics simulation or whatever..

The problem that I have had and many others complained about is that the mesh file found on the Bioloid CD was not exportable or transferable to other systems. The bone hierarchy disposition seem to be messed up.

We finally cracked the problem and found the cluprit. The Chest bone (which is second to the root bone) has a mirrored Y axis. At least when used with Fragmotion (i tried with other tools and got similar or worse skeleton mess).

Here's a procedure for importing and exporting MotionEditor compatible mesh files.

Run fragmotion, Import Humanoid.x from the Bioloid CD (for example)

The bones look all messed up. Mirroring the Chest bone (2nd from root) along the Y axis, will fix the bones.

Export as .X file.. opens dialog.. select Text format instead of compressed.

Edit the file with your favourite text editor and find the list of 16 numbers of Frame Chest -> FrameTransformMatrix

Change the 11th value from -1 to 1. Save the file

Import the modified Humanoid.X text file back into fragmotion and now the bones are located in their right place.

[BillB]

Thanks Limor.

Any chance of posting the corrected .X file on RoboSavvy?

[ryann2k1]

Hi..
I have figured out the messy bone, but after I import .X file to fragmotion, the whole body becomes black (the textured is black), the original color is gone. anything that I missed?

thank you..

cheers

ryann2k1

[BillB]

Have exactly the same problem - black bioloid model and a huge text file.

[billyzelsnack]

Just a random guess, but flipping the bone might also be flipping all the triangle normals.

[limor]

hi, don't know why you had that problem with the flipping of the meshes. it could have to do with conversion to/from text X file.

In any case, here is the corrected .X file (text version in Zip archive)
http://robosavvy.com/Builders/limor/bio ... rected.zip

[BillB]

Thanks Limor

[ryann2k1]

Hi..
It is really strange...I have used http://robosavvy.com/Builders/limor/bio ... rected.zip
but the body still remains black..
How did you figure it out Bill?

cheers,

ryann2k1

[BillB]

Oh - I had not actually tried the file before I posted my thanks.

Unfortunately the file Limor uploaded does not work properly for me either - all I see is a black model (albeit with the corrct orientation of the bone structure) .

I am using the latest version of fragMOTION (v0.9.1a). I also tried using the DirectX viewer that comes with the DirectX SDK - but the file manages to crash it. And no Joy with Blender (where the whole robot appears as a Cube).

Any suggestions Limor?

Bill

[limor]

indeed it does come out black in fragmotion for some mysterious reason.
but the mesh and skeleton are fine. Try to export the mesh+skeleton to in any other format from fragmotion, it should be ok.

I exported it to Ogre3D mesh files and had only 4 bones that were slightly distorted but easily fixed (I havent figured if the problem was with the mesh file or with my EZphysics simulator reading/writing the transform tensor incorrectly).

BTW: an interesting thing about Bioloid Humanoid.x bones -- You will notice that every servo-axis-shaft bone has a daughter bone. It seems that these indicate the location of the center-of-mass and inertia tensor axis for every sub-mesh. We are not sure about but i'll run it by Robotis and see if this is a by-product of their CAD system export function.

Regarding Blender - I burned away too many brain cells on 3D-studio-max and Blender is a completely different beast so dont know why the imported mesh is inside a little cube. i had the same issue last time i tried to play with blender import function.

[ShreddinPB]

Hey guys.. I fixed the "black model" problem, atleast its fixed in fragmotion.. someone can try and load it in.

Basicly what happened is this, when you switched the scale on the joint from -1 to 1, it also inverted all the geometry. I have worked in 3D for a long time so I just loaded fragmotion and "flipped the normals" so they are all facing out.. basicly we were looking thru the geometry and seeing the back side.. in fragmotion you have to do 2 steps to succesfully flip normals since it doesnt work with face normals, and only with vertex normals.

Basicly just select the geometry.
under the "Face" menu select "reverse vertex order"
under the "Face" menu select "reverse vertex normal"

voila! fixed!

Also, the file size issue you guys are talking about is because its being saved as an uncompressed text file. I saved the same .X file as a text, and a compressed binary.

Text is 13 megs
compressed binary is 1 meg

I have the file ready, but dont know where to put it so that it is on the RoboSavy site itself.. I can host it on my server.. but would rather it be self contained here..

[limor]

great ! thanks!
to upload the file to RoboSavvy please use the My Files link on the left User-Menu

[ryann2k1]

Excellent..That was a great job..
Thanks a lot....

cheers


ryann2k1

[ShreddinPB]

great ! thanks!
to upload the file to RoboSavvy please use the My Files link on the left User-Menu

That did it.. here you go guys
http://robosavvy.com/Builders/ShreddinPB/bioloid_x_file_corrected_v02.rar

awesome progress!! cant wait to be able to write out my own motion files

[smoothchat]

The trick now would be to modify an original 19DOF .X file into a 19DOF Hybrid (a 19DOF robot built like an 18DOF with the 19th servo at ID19). I have had no success in reassigning the Bone IDs so that the model appears correctly in the motion editor. Everything's packed away at the moment (moving house). I will tackle again later in the year.