I am Filippo, and I am struggling to understand what is happening here. Here is the matter.
Using Rhino 5, when I export my model to OBJ and I try to open the the file in 3ds Max something goes wrong.
Most meshes are ok, but some not. They look broken.
Well, the point is, I have been using Rhino 4 for some years and I have never experienced this weird “bug”.
I tried every single combination in the export option.
The only solution I found is, well, save the model as rhino 4, and use rhino 4 to export a good OBJ.
And this is what I am doing.
Note that I want to keep layers (not objects name) as mesh objects.
But I am sure there must be a solution for Rhino 5.
Hi Filippo- please post here or send the file to tech@mcneel.com - it looks like a meshing problem and not an OBJ one to me, but I’d like to have the file to look at- just send the one part that messes up, that will be fine.
I also am having a huge issue with Rhinos OBJ exporting. I have been trying to export my models out to other program such as Quixel, Toolbag, Substance designer / painter and Photoshop for texturing. I have not had any success at all importing into Quixel, Toolbag it’s 50/50, and Substance will usually crash after a period of time. Quixel and Photoshop only import OBJ, Toolbag and Substance will import FBX and OBJ. With OBJ being the most universal accross platforms and programs, it’s really frustrating not being able to export OBJ from Rhino! Even Meshlab crashes every single time I open a Rhino made OBJ. Not having this problem with other OBJ’s from other sources, just Rhino’s. Even importing Rhino OBJ’s in other programs like Blender will make it crash. I should also mention that if the program does’t crash then 9/10 times I get wicked artifacts in the model. I use OBJ or FBX because it is my understanding that those are the only two formats that save custom UV data and well everything can open an OBJ file. So whats up with OBJ?
Try unchecking “wrap long lines”. This was the source of incompatibility I’ve run into, years ago.
I use .obj very frequently and never run into crashes here. The different mesh results probably really
have to do with changes in the mesher, it hasn’t become worse overall. You just need to tweak some settings,
probably best by object (in properties panel).
Good. Wrapping long lines imo really should not be turned on by default, I frankly wonder why it’s there at all.
If I recall correctly of at least 5 programs I tried only Blender could chew .obj’s output with this setting checked.
Also the exporter shouldn’t try to create Ngons by default (spoils exports to Zbrush) – this setting should at least get exposed in the Exporter panel. Maybe @tim could take care of this?
I think the line wrapping was implemented for, and most useful with, exporting nurbs objects to OBJ (a long time ago, before I started working on it, not that it matters). I will make sure that it’s not the default in a future release. I could grey it out if the object type is set to meshes, is that useful or overkill?
The ngon stuff can be enable/disabled with the command line version of export now. Not sure why it wasn’t added to the dialog version but I will also make sure that it’s added in a future release. Just curious, does Zbrush have issues with quads too or only polygons with 5 or greater sides?
Hi Tim,
thanks for having a look! Greying this option out when not applicable would be very helpful, please do so.
My guess is that nobody uses the Nurbs option anyway – there’s far better Nurbs Exchange formats.
While theoretically supported through the format I don’t know a program which can import obj as Nurbs.
Those two apps which might do 3DS-Max + Maya(?) due to Nurbs origins read better Nurbs formats too.
Thanks!
[quote=“tim, post:9, topic:15732”]
Just curious, does Zbrush have issues with quads too or only polygons with 5 or greater sides? [/quote]
Zbrush is a sculpting program which relies on Subdivision Surfaces, it reads and writes triangles but prefers quads. Ngons are randomly broken into triangles at import time, which in the case of Rhino is a problem as V5 doesn’t support these living in the viewport but tries hard to create them via obj-exporter. One therefore in Zbrush gets confronted with a mesh which has a deviating topology from the mesh sent from Rhino – which is pretty unexpected.
As a general remark – although often requested Ngons aren’t universally cool or desirable. Their best purpose is to reduce polygon count, which only plays a crucial role in certain render engines, such as Vray. Apart from that Ngons in terms of Catmull Clark subdivided geometry are rather undesirable and avoided, if possible. They – like triangles tend to create artifacts in renderings, especially when animated.
after all this years looking for a good explanation about why obj export from rhino became broken or crappy geometry ( lets say in 3ds) you give the explanation for it.
I found only MoI (moment of inspiration) can export all objects i obj format without issues.
We architects-rhino users need to build all kind of scenes that need a lot of object s assets.
i hope Rhino 7 will bring this options more accurate.
Hi - could you explain the specific issue here? I’m afraid there’s nothing in your post that could lead to any changes in what Rhino does or doesn’t do.
-wim
Its like after export obj from Rhino and open it inside 3ds max the object it self results are not smooth as it is inside Rhino. And the edges are not stiched end became broken and open.
I think i can post the Tap water (example) here so you can test.
