I’ve been posted the problem before, but I haven’t found the perfect solution yet, here is the details
I know that sounds silly, but just try to re-tessellate before unwrap.
Hope that helps
CheerEO
Marco
Oh yes, sometimes UV mapping can be a pain in the a…
Been there multiple times, even with super easy shapes.
As @marco.wodarz suggested re-tessellating it, maybe this helps.
Or have you tried to set a second Direction Guide on top of the pipe?
I don’t know how to set the second direction guide, by the way, I’ve tried to re-tessellate before unwarp, it didn’t work
I’ve tried re-tessellate before, but it didn’t work
Like Philipp says, the UV mapping can be a pain. What I miss inside KeyShot is being able to actually see what the UV-map looks like. So I never use UV-unwrap from KeyShot since I don’t feel I control much of the process.
This is for example how I think it would be in a pretty ideal scenario for a bent pipe like the one in your example.
In your situation with the kind of renders you create I think you need to search for a kind of 3D pipeline which doesn’t make every render a frustrating experience.
I’m not working with nurbs but if I’m correct you can’t UV unwrap them unless they are polygon/vertex based models.
Since you need that UV-map in case things are brushed or have a pattern otherwise it might be worth considering to look for tools that can do the conversion before you import them to KeyShot.
If you use SolidWorks and SolidWorks can export nice geometry as fbx/obj etc it’s worth it to use that as starting point since SolidWorks ‘knows’ how the object is created and that should give the best and cleanest geometry. And I guess you can tell it how fine you want the tessellation to be so you keep the triangles in a normal range which later on saves you render time and time in creating an UV.
If you have the fbx/obj you use that to create a neat UV-map for those parts in the model who need it. So you have to find a nice program which you can use to do a UV-map but it would also be nice it could be used to throw away parts of the model you won’t see anyway. That again makes creating the UV-maps way easier like I showed above.
So your pipeline would look like this
That looks like a lot of steps but I you find the right tools for the job it will really save you a lot of time I think. Most of those UV-unwrap programs have automatic features as well so you can use those. It’s just that with the bend parts the UV maybe needs to be done manually. Although there might be smart software that can figure it out as well.
Like I said, I’m not used to NURBS modelling and I’m not in some kind of business I need such a ‘pipeline’ for the things I do. But while it needs an investment in research/time I think it will save you a lot of frustration later on when it comes to rendering.
I’m sure others have more experience with this kind of workflow and might be able to give you some more in-depth comments about the software they use.
And maybe KeyShot can also create the right UV-map for this object, I don’t really know. Before I would use the UV-unwrap in KeyShot I really need more visual cues about what it’s doing like a flat UV map preview.
Well said and explained - Kudos to you!
Can you suggest any of those UV-mapping tools? Which one did you use for the pipe?
Thanks! That in the example above I used the UV-mapping tool inside MODO. For me that one makes sense so I feel like I’m in control while it doesn’t feels really complex now I’m a bit used to it. But it’s manually done. If I do it the automatic way in MODO it’s more like this:
That would not give you distortion though but a lot of seams which are not needed.
For fun I dropped the .obj in a auto unwrap program which is called ‘Ministry of Flat’. It has only a few settings and only supports OBJ I think but it uses a really smart algorithm (it says).
This is how the (weird) interface looks (it constantly moves around):
It did this in 6 seconds (very simple). But I was surprised it actually made a square.
So I opened it in MODO again to see what the UV looked like and it even did a better job than me, well it compensates for the bend in the UV. Not sure if needed though.
In some feedback I gave for KeyShot I also mentioned this program. It seems that Cinema4D now also uses the algorithm from Ministry of Flat and I though it might be worth to take a look at so within KeyShot you can unwrap things with just one click.
They have a demo I think: Ministry of Flat - Fully Automatic UV unwrapping. (quelsolaar.com)
edit: to add, ministry of flat can also used by command line so you can implement it in a 3D pipeline quite easily
For the second direction guide:
Set the first one, click “check” and repeat the same step.
That should do it.
Thanks again for this detailed explanation and insight of your experience - you should teach or give tutorials! 
Never heard of those applications, but they look promising.
Will try them and hopefully end up with better UV maps.
Thanks again!
Cheers!
LOL thanks! I’ve not always the feeling I do things the right way since I did all education myself The big advantage is that you also know about a lot of problems and struggles others experience since you’ve been there.
MODO is basically a program like 3DSMax. But I tried multiple times to get rid of Sketchup (in which I modelled a lot) and learn 3DSMax but it doesn’t really fit my brain or so. When I saw MODO existed I tried some tutorials and got really enthusiastic. I’m still not great with modelling but in MODO it’s at least fun. If I look at other forums MODO is well known for their great tools in hard surface modelling and it is also friendly (well, as much is possible) in UV-unwrapping.
For UV-maps you could also take a look at 3DCoat or RizomUV they both have weird interfaces but some love them for the UV stuff.
I’ve tried with .obj format, one of the pipe ends is straight following the shape, but the other end which is curved didn’t follow the shape well, image01 is the end that correctly UV mapped, and image02 is the unperfect one.
And what you mean is that do uv map in the modo and save it as obj/fbx, and do the rendering in the keyshot, am I right?
Same here, I learned Keyshot all by myself (of course, watching lots of tutorials, try and error and asking other rendering specialists such as Oscar Rottnik )
But that’s how it’s done, right? Try and error, learning from your mistakes and sharing your experience with others - great foundation for teaching or making tutorials.
I have been thinking of this for a long time and I might start soonish…I might not be an expert and know Keyshot 100%, but I might know one or two things which others don’t know.
As Jim Kwik said:“The best Student is also the best teacher - and the best teacher is also the best student.”
or as David C. Baker said (even more relevant for me):“Not only do you help them (students), you help yourself, because you gain claritiy through articulation.”
So what I am trying to say here: give it a shot! 
Ah, okey, never tried 3DSMax or MODO…currently working with Fusion 360, Inventor and used to work a lot with Rhino. Tried Blender, but gave up because I was missing the constructional clarity of CAD software. I guess I should try Blender again for better UV mapping.
Nicely done!
My idea was not so much using MODO, that was just an example since I used it, but more creating a 3D pipeline with software that fit your situation/scenes well.
That could mean using different and multiple software for your work but in the end you might gain a lot of time if you can prevent these kind of puzzles or for example really high render times because you have such dense tessellation.
From what I’ve read lots of companies who have lots of renders (of the same kind) try to streamline the process as much as possible and that could mean that KeyShot is just the renderer indeed. And it could be that every renderer as final step goes through some image tools for extra contrast and a consistent look between all renders.
It depends on your own situation. For me every thing I do is so different that such a generic pipeline of applications doesn’t add anything. But since your renders/scenes consist a lot of the same kind of objects/materials/environments you might save a lot of time in the end if you can streamline the entire process.
Really nice you managed to do it with KeyShot in the end. Can be really useful for others as well to know it can help to add some more direction guides.
Another option is trying to use Blender as the benefit is that is truly free application and has a full suite of UV unwrapping tools to your disposal. I am personally still rather new to UV Unwrapping in Blender, but I have had some success is using it. We have a Blender specialist on our team that definitely has more consistent results, so I am sure once mastered, it would be a great tool to add to the belt.
With that said, UV Wrapping is a polygonal model concept and when creating models with software like Fusion, SolidWorks, or CAD with NURBS in general, things don’t often line up and even when converting CAD to a polygonal workflow, the mesh tends to be all over the place and the topology is often very bad. There are many cases where certain parts that are more problematic in UV Unwrapping require the part to be completely remodeled in polygonal software like Blender, C4D, MODO, etc. In Raymond’s case, the object is fairly simplistic to recreate in polygon format with much less geometry and created using quads instead of tri’s and ngons, that a UV Unwrapping engine would have a much easier time to determine how to properly map out the faces.
To be clear, I am not bashing on CAD and NURBs modeling, as there are clear benefits to it, especially when you are an engineer and need absolute accuracy in dimensions, but there is a reason why polygonal modeling is the industry standard still for VFX, game asset creation, and hard surface modeling for pretty much anything outside of manufacturing. Keyshot was originally created for engineers and manufacturers to create great looking 3D renders with CAD, so NURBs and CAD are fully supported by the software and probably better than any other software out there, but when trying to apply polygonal workflows to CAD, there is often some workaround that is required.
Yes, I was thinking about picking up Blender as I think it is an open and powerful tool, too. But it will take me so much time on learning it from scratch, this is what I stuck with. Anyway, I will try my best to pick it up, I hope I can do it.
Here is a pretty good UV Unwrapping tutorial by Blender Guru. It should get you started. https://youtu.be/scPSP_U858k
If you familiar with basic functionality of Blender, this should be pretty easy to follow.
Thanks, I’ll give it a try
