Please support material per face when exporting to other render engines

[cekuhnen]

Hi all,

Fusion API does not currently support the export of Material per Face and this is very crucial to have when working with furniture design and laminated surfaces when using for example the Thea Render plug-in.

Any idea if this could be easily added? Only being able to export body materials is not always everything you need and you dont want to make a special render model for separated faces to export!

Claas

[marshaltu]

Hello,

Material seems to be not meaningful for "face". We cannot assign a material to face of a body in UI. Instead we do support appearance per face. You should be able to extract rendering propeties from "appearance".

Please let us know if it cannot meet your requirements.

Thanks,

Marshal

[cekuhnen]

Hi there

Hi Marshaltu I am talking about material / shader / texture for render engines and not materials for the physics engine.

Fusion API as far as I know can only extract the appearance from a body and not a face. That is a hughe problem for me.

Can you please add that to the API so engines like Thea Render can use it?

[ekinsb]

The BRepFace object supports the appearance property which returns the information that defines how that specific face renders.  Typically, this will be the same as the body, but it doesn't have to be.  The appearanceSourceType property tells you if the appearance of the face has been inherited from the body or part or if it is a face override.  This does mean visiting each face in a model to get its appearance information.

[cekuhnen]

@ekinsb Thanks for the reply. I was under the impression that the API does not offer this. I have to check.

Also what is the status of UV coordinates export when generating a mesh based on the BREP to send to an external render engine.

Have not found that in the API.

[grakoczy]

To be able to export multiple materials per object there must be the way of getting triangulated mesh data for given material. Without this having material information for BRepFace is useless as one face can be converted into multiple triangles during use of meshCalculator.

[cekuhnen]

@grakoczy @ekinsb

Yeah and that is what I would need for proper rendering.

If a product has just one material / appearance this is fine.

But when for example I create a woo table top with laminate on the top suface I deal with two different apperances / materials

and when exporting each apperances should result into a mesh that gets their unique material in the render engine.

A work around would be to make a render model, split the faces along apperances.

But honestly as a professional tool you do not want to require your users to do that.

[grakoczy]

If meshCalculator could take material as parameter it will solve the problem. In this case I'd have separate mesh data for each material used in the body.
This and UV coords will make body export more or less complete.

[cekuhnen]

@grakoczy@ekinsb 

Yeah, that is the way this should be so a designer can do renderings meeting professional requirements.

[ekinsb]

I agree that there are some things we can do to make getting the meshes and appearances of the entire model more efficieint, but it is still possible with what's available in the API today. What if means for bodies that have face overrides is outputting each face as a seperate mesh.  As long as the tolerance is the same when creating the meshes, they will still be watertight.

Regarding getting textures and texture maps, we're waiting on a Fusion change before we can expose that through the API.  Fusion is also using more procedural textures for many of the appearances so there is no texture map in those cases.  It's likely that procedural textures will continue to be used more in the future because these produce a more realistic result, especially as the texture goes accross faces and looks different depending on the orientation, like wood grain.

[grakoczy]

Thanks, I'll try per face approach to see if it will work. 

[cekuhnen]

@ekinsb

The procedural wood  you have is an interesting addition, I use this approach since many years but it always fails with bend parts. And it would only be

really usable when doing solid wood renderings. The moment you need specifica veneer cuts you hit bumps again.

UV mapping export of BREP/NRUBS based CAD data is still needed simply so in every other engine you can use the UV mapping mode without having

to extra unwrap the mesh. That is the beautiy when you get mesh data from OBJ.

So it does not matter if a Fusion material does not carry over - what we care as artists is the UV mapping so in an external engine we can create

the materiall we want there and then use the proper UV mapping.

[BrianEkins]

I know this is an old topic, but I ran into it while searching for something else and wanted to comment that the UV mapping of the mesh associated with a face is now supported.