Mesh for Mac users with Cheetah 3D

[Gavin Hird]

I have found that models made in the Mac appliction Cheetah 3D and exported to COLLADA loads very nicely into SecondLife (and opensim). 

Even if there is a learning curve, it is significantly less convoluted than Blender, and Mac users should faster feel at home and be productive.

It is available from the Mac App store, but I found it was much cheaper getting it directly from the developer web pages.  The developer is also fast to respond to requests, and the collada models exported now displays and opens in OS X 10.7 Finder and Preview. 

An in-world example of a model made and exported in Cheetah 3D can be seen outside my store in Concinna (the Boötes logo.)

I am working on creating a rigged mesh for Cheetah 3D based on the simplebot rigging. 

One shortcomming is that it can't open other collada models, but it supports a number of other commonly used formats. 

 

[Silverthumb]

I would be interested in a rigged mesh from C3D as well. I have been working to get something usable out of Cinema 4D R12, but can not get the weights to stick on import to SL.

Since viewing your post, I have tried the following:

• Export avatar.blend file from Blender 2.49b to FBX file. It seems the joint rotations come out better from this that taking a DAE file out of Blender. ( in C4D, DAE seemed tobe rotated 180 in the Z axis)

• Imported into both Cheetah and C4D, both of which seem to like the rotations better, and weights come over cleanly (previous attemtps from Blender to C4D loose weights in the process. I re-bind in C4D, export, but nothing will come over to SL with weights). 

• Saving out a DAE of the avatar.blend file from Cheetah gives good weights, but the bodel comes in rotated -90 in the SL preview. When you choose 'Show Skin Weights' on import to SL, I have the actualy geometry of the C3D bones weighted to the avatar correctly, and they move well, but the actual mesh is gone!

For the life of me, I can not understand why LL does not provide a simple DAE or FBX rigged avatar file(s) for creators to build from. I have been using Silo/Cinema 4D (and at times, Cheetah 3D, Modo) for years now, and I am just not much of a fan of Blender's crazy interface and mouse controls. When the mesh beta first started last year, I was sucessfull in taking a custom avatar mesh into Blender, rigging it and importing it into SL. Now when I go back to test some of those old meshes from intentory in Aditi, SL throws a message saying the format is incorrect - so, since I am starting over from scratch, I just want to use the tools I have with an open file format.

Anyway, thanks for putting this out there an I will share anything I may come up with in C4D/Cheetah 3D

[Gavin Hird]

There is, as you say some odd rotation issues when setting up a rigged mesh based on avatar.blend or simplebot.blend. 

I get the model to import, but the weight map and the joints are not able to be included (if selected in the Modifier tab the upload button disappears.)

I can see the weight map in preview but it is rotated 90 deg on the model. The joints are also visible in preview, but look odd (bigger and displaced.)

I will try two venues; create a skeleton from the ground up in C3D, and do the same in DAZ Studio 4 with the content creator tools and see where that leads me. 

In DAZ Studio there is a rigged SL avatar, but the bone names are different from the standards document I found in the wiki. I'll try and import the one from DAZ as is and see how that goes. 

[Gavin Hird]

We finally figured it out this morning and the key is to have the skeleton rotated to a horisontal configuration along the x-axis and align and scale the model to the skeleton.  You must then, with the model selected, from the Tools menu select the Coord System tool and then Burn Transformation. This will reset the coordination system of the model to be identical to the skeleton.

After that you can apply the skeleton to the model and bind it. I found the heat weight map method works pretty well.

Now for the export, there is a catch right now as version 5.8 of C3D updated the export to be per standard and in compliance with what works OS X 10.7 QuickLook and Preview app. Unfortunately that broke the import to SL as the joint names are no longer written to the Name_array block in the collada file. This is required by the SL viewer for successful import of the joints and weight map.

It is possible to edit the block manually in an editor and replace the 26 IDs with the joint names in the same order as they appear in the skeleton in C3D. After that, it is smooth sailing into SL.  Hopefully there will be an "SL friendly" export option for collada, so this will be fixed.

It is possible to export to FBX, run it through Autodesk's FBXConverter with collada as output, but I have found it garbles the weight-map but the joints are fine. There might be version issues that comes into play here...

So yes, it is possible. Right now it requires manual editing of the collada file (which is really just a copy and paste after you have done it once), and hopefully we will have a fix in a few days.  

[snakeappletree]

I was glad to find this forum here!
It is the closest thing to 'upload from Cheetah 3D into SL beta For Dummies' the web has to offer. 

I am 1 month into SL and have been using Cheetah 3D for a while (I am using v5). 
Yesterday I attempted uploading my first ever design into SL beta from Cheetah. 

Problem 1: scale. I had to downsize it in Cheetah and re-upload it, in this process I discovered that I can upload tiny items and then stretch them in SL to avoid paying extra Lindens for larger items, without losing any shape detail. 

Problem 2: skin / texture / wrap (various names for the same thing across different platforms). Although the original object in Cheetah has 2 different surface colours in Cheetah, it uploaded with none and defaulted to black in SL beta. I haven't figured this out yet.

As I said; process For Dummies ... 

Any and all guidance and help I can get will be muchly appreciated, not only by myself and others in same situation but also by the hordes of fans lining up to experience the really wonderful 3D artwork and environments that I am obsessively constructing night after night (by which time oculus rift will probably be out-selling game consoles).

[Gavin Hird]

To answer your problem 2: 

Cheetah does not export the textures with the dae file, but it will preserve the material zones which when imported to SL corresponds to faces. Your imported model should have 2 faces which you can apply your textures to once imported separately into SL.

If you  have used a Cheetah material that is dark, SL tends to import the face colored in black. Just remove the color when you apply the texture in SL, and all should look fine. 

[snakeappletree]

Thanks Gavin, I will let you know how my test following your advice goes. It did import my previous test upload as black.
Import model has 2 faces; does this mean a maximum of only 2 texture files can be allocated to a model?

Cheetah3D has internal textures including glowing lights, water effects and reflective metals, all of which I use inside the program while building, as well as uploading custom textures (eg; from photoshop). I am hoping that SL can deal with mirror effect textures, without causing lag.

[Gavin Hird]

Any mesh can have up to 8 faces, also when exported from Cheetah3D.

Creating a multi faced mesh can be a bit of a pain in Cheetah3D as selecting the polygons belonging to a face is far from intuitive.  I have found that if you spread the uv of each face outside the main square of the uv canvas, it is later easy to select and manipulate the uv for each face without interfering with the uv for another face. Then also the uv map doubles as a selection tool for the polygons in the mesh, and it makes it extremely quick and flexible to work with.