Hi Stan, MoI does not itself have any built in concept of a local axis belonging to each separate object so right now at least that information is just not present for MoI to deal with at export time either. Also on top of that some file formats might not support it too, like out of the ones you list OBJ format does not have any mechanism in it to represent it either.

Then on top of that, "plain geometry" in CAD formats like STEP, IGES, SAT, etc.. which you are using for the NURBS to polygon conversion also do not have an object axis attached to them, it's only "assembly instances" that will have that. Some files may be made up of assembly instances that have that data in the CAD file but it's also entirely possible for other files to be just plain geometry and not have it.

In the future I want to implement instances in MoI and hopefully after that I'll also be able to make axis information for those instances at least to get exported to file formats that support them, I'm not sure when that will happen exactly though.

In the meantime if all you need is to get all the axes in Cinema4D to be centered around the object's local bounding box center rather than at the world origin, there is a command in Cinema4D that will do that for you. On the old version of Cinema4D that I have for testing it was a command on the menu under Structure > Axis center > "Center axis to". On newer versions it looks like it may have moved under the Mesh menu somewhere. Select all your objects and then run that command and each object's axis should move from the world origin to the center of that individual object's bounding box.

There's an example of using it here:
https://www.youtube.com/watch?v=g_VZXbu7iL4

- Michael

Hi Michael,

thanks for a thorough explanation. We have converted some SolidWorks STEP files using Okino Polytrans and we were able to get local axis for all objects including rotation info - this was very important to us, because then we can (in CINEMA 4D) replace lets say all small elements like screws with instances, which can save insane amounts of memory when rendering very complex objects. But Moi's output is much better in many cases, so I would rather use MOI for some tasks. I am aware of Axis center command in C4D, but unfortunately this cannot "detect" object rotation.

But anaway, I would like to thank you for making such a great product. For now, we are using it just for conversion purposes (and it is really great for what it does, maybe just 64bit version would be really helpful), but I am sure we will dig more into it.


Best regards,

Stan

Hi Stan, yes the problem you're running into in this case is that MoI does not currently support instances, that's the difference.

In the future I do want to implement instances in MoI and then also make STEP import read those instances, and also make exports use instances when possible as well. That's a kind of long chain of work involved in implementing all those pieces so I'm not sure when that full sequence of stuff will be done. Then on top of that only a few file format export types support instances in them, for example there is no mechanism in OBJ format for doing instances so it would only be for a couple of formats maybe just FBX, I'm not quite sure.

I am in the process of investigating doing a 64-bit version so hopefully that will happen for the next version.

- Michael

Hi Michael,

We are using .abc (alembic) since a little while to export/import stuffs in our 'polygon' pipeline.
http://www.alembic.io/

I'm pretty sure this stuff support instances description.
Even if the main purpose of this format is to export animation data (stream file), it seems much more 'solid' than anything I have used so far (.fbx, .dae).

There is no real need to have an .abc export in MoI, but maybe it might be an alternative to .fbx in the future to handle instances.

Hi Pascal, yeah once instancing is in place inside of MoI it will probably make sense to do some new file format support after that to use some formats that handle instancing... alembic could make sense at that time. I'm not really familiar with it myself at all so I don't know what's really involved. I guess Collada is the other one that's meant to be similar is that right?

How is it that alembic is more robust for you than Collada, is it newer and supports more kinds of animation stuff?

- Michael

Hi Michael,

Well the point with alembic is that it's 'just' export a point cache of you animation, meaning that exchanging animation in this format overcome a lots of trouble you usually have with Collada or .fbx. But that's something very specific to poly modeling/animation industry.

Now, I don't know the reason, but it's the first we were able to export data between different software (modo, 3dsmax, realflow, clarisse) without having to care about z-up/y-up problem, wrong normals, lost uv's, broken uv's, bad triangulation, to name a few.

Of course it's jut my limited experience so far, maybe it doesn't work that great for other users ;)