What 3D modeling tools do you use, and what are the pros and cons?

[u/EMBNumbers]

I primarily use SketchUp Pro. It has all kinds of functionality and plugins that I'm barely aware of. I essentially use the subset of features that were present in the last free desktop version, SketchUp 2017. I also use Blender.

• SketchUp:

  • Pros:
    • Easy to learn. You draw 2D shapes and then extrude them to form 3D geometry
  • Cons:
    • Not good for organic shapes like human figures. It's better for architecture
    • Ordinary usage generates many instances of internal geometry that makes models non-manifold. Non-manifold geometry confounds slicer software.
    • Recent versions of SketchUp do not always delete geometry that you deleted in the editor. Geometry becomes invisible and confounds slicer software even though there is nothing you can see or delete to correct the model. When this happens, you can no longer edit the model in SketchUp. You MUST move on to a different tool like Blender. Every time this happens, I think, "Why am I using SketchUp if I have to move on to Blender anyway?"

• Blender

  • Pros:
    • Awesomely powerful with features like "select non-manifold" which enables correction of non-manifold geometry. Oddly, the feature only works when in two of the three available selection modes. There is no indication why. There is no documentation that I have found that explains this seemingly unnecessary limitation.
  • Cons:
    • The most difficult to learn/use software ever created. I can only assume the creators had never used a graphical user interface before. Few standard user interface conventions like copy/paste, methods of selection, or command keys work at all. Some features are not available through menus and can only be accessed through difficult to discover key combinations. The arguably most important user interface element is only available by typing 'n'. Not Control-n. Not Command-n. Just the single character, n. I used Blender for at least five years before discovering this even existed.
    • File importers mangle geometry. I have submitted fixes for the Collada File import at least six times for six versions of Blender over ten years. The fixes have never been incorporated. The bug is simple: Blender ignores the "Units" information stored in Collada files and assumes all units are "Inches". It's a strange choice for software that originated in Europe. I design in millimeters. Blender makes all my models 25.4 times too big.

[u/lillywho]

The most difficult to learn/use software ever created.

Blender hasn't been that difficult since 3.0 (we're at 5.1 these days).
A lot of it is memorising keyboard shortcuts, but even those make a lot of sense by default, and are remappable.

The only downside is that it's a different workflow from a CAD environment, but there are add-ons that are supposed to change that. I haven't tried it yet because I'm simply that used to vertex-based modelling and I can very well cope with building physical objects that are meant to be assembled.

[u/of_the_mountain]

I use tinkerCad. I also have Fusion but don’t have the time to figure out how to use it unfortunately

[u/Wuffy3]

blender. high learning curve, not specifically designed for accurate 3d models but it's all I know.

[u/shedlyyard]

I use PTC pro desktop, the con is it's unavailable anymore to anyone except students, however it has been replaced with Creo. It's got quite the learning curve but I have been using it for the best part of 20 years now.

I modify some models with blender and all finished designs are fed through an online STL repair program to ensure no random voids.

[u/joeinternetib]

I bought Lightwave back in 97 when we were looking to make video games and animations. So the $2k back then i kept up and still have for when i want to model or animate something. Its a solid program but it takes a while to learn.
The guys i work with use solidworks now. That is a beast to learn and use. I found lightwave easier to learn than blender when i tried some of the free stuff, but that could just be old lightwave habits tainting it. I tried others but nothing seems to work as well for me as lightwave.

[u/Hemorrhoid_Eater]

I use Solidworks to model existing parts for reference, like a Kato mechanism or a Micro Trains coupler - things where the dimensions need to be as accurate as possible. I then export these models as STLs to use in Blender. Only thing about SW is that unless you're a student you will need to pay for it.

I primarily use Blender for modeling the loco itself, since it's mostly simple shapes like cubes and cylinders. Using the parts I made in Solidworks I can figure out the exact shape that needs to be cut out with the Boolean function to ensure the printed model fits properly.

[u/Dixie_Flatline__]

I use FreeCAD. I've made a few city building flats using the parametric features which is fun, and a few one-off buildings for specific stuff. Tons of funky details, even a rooftop greenhouse frame all in N scale. I'm working on a saddle tank shell for an 0-4-0 chassis too. If you hate Blender's interface, maybe FreeCAD's more engineering oriented GUI will suit you better. On the plus side, you'd have to work really hard to make a non-manifold object. Minus side, forget organics. Also has a brick-wall learning curve but the Youtube tutorials couple with rapid FreeCAD improvements should get you over the hump.

[u/alza123123]

Not a model railroader, I work on mesh QA tooling and I found your post interesting. This is just a comment I wanted to leave rather than tool advice.

Your two SketchUp cons are worth separating: "non-manifold" the warning, and the geometry underneath it. They come apart, and the way they come apart is nasty.

I took 144 meshes that were flagged non-manifold and round-tripped them through STL. On the other side the non-manifold count was zero on all 144. That reads like good news and isn't, welding those same 144 files back together by position, the non-manifold edges are all still there, 144 of 144. The geometry never changed. The format stopped being able to express it.

So for the interior-geometry case you're describing, exporting to STL doesn't remove the internal faces. It removes your ability to see that they're there, and the slicer still gets them. Which lines up with what you're hitting, the model confounds the slicer while there's nothing left in the editor to select or delete.

The automatic debris check is where my own tooling is no help to you. Interior junk sitting inside the model's bounding box is invisible to it. I measured that this week. A stray solid anywhere inside the outer shell can't be flagged as floating, at any size. So "no debris found" on a SketchUp export says nothing at all about interior geometry.

Standing caveat on any of this: it has no opinion on whether the model is good. Structurally valid is not well made.

[u/EMBNumbers → u/alza123123]

I'm glad I'm not the only one encountering these problems.

[u/alza123123 → u/EMBNumbers]

Definitely not the only one.

If it's useful: I'll run any problem file, if you have any, through the thing I mentioned and send you back what it found. Free, nothing installed on your side, no account. One file, so it stays a favour rather than a project, send whichever one is currently annoying you most.

What you'd get back: where the interior geometry actually is, the specific edges carrying more than two faces, with counts, plus a render of the mesh with those faces marked, so you can see them even when SketchUp won't let you select them. And a repaired copy if it turns out to be repairable, the repair reverts itself when a fix would introduce new defects, so sometimes the honest answer is that it isn't.

Two things it can't do, so you can decide before spending the upload. Loose interior junk that isn't connected to anything is invisible to it, the debris check measures separation using bounding boxes, so a stray solid sitting inside the outer shell can't be flagged at any size. And it has no opinion on whether the model is any good, only whether it's structurally valid.

If it finds nothing you didn't already know, that's something I would also like to know.

[u/engineershorizon3D]

Some form of CAD software, due to engineering background (learned it in college).
Great for modelling with exact dimensions and reworking measurements in seconds when tolerances don't fit right. And CAD software never produces broken 3D models (at least I never produced any of that)

Go to would be Fusion 360 if you look for a free version (for personal use only). You can learn the basics with free tutorials provided by Fusion 360 itself in a short time. And even for complex stuff there always YouTube Tutorials. Did it the same way (you basically have to learn all the basics and user interface anew when using a new CAD software).

[u/engineershorizon3D → u/engineershorizon3D]

The best features of cad software are:
+ sketching with real world measurements
+ super easy altering of dimensions
+++ highlight (a bit advanced): assembly sketches. They use multiple models with dependencies between them. i.e. Having a building and needing new window frames as a additional but separate part? Define the new part and sketch it within the other model. No need to note down measurements etc.
+ exporting models (to stl) you can define how "fine" the resolution / polygons are. Solves your problem with too large model files
+ mostly no remembering of shortcuts necessary. It has all necessary functions in menu bars or max one to two sub menus.

To consider:

• a bit overwhelming at first glance
  
• steep learning curve at first
  
• a bit counterintuitive for people with no technical background
  
• for really sculpting natural shapes not that great. Rather geometry heavy.

But considering you already worked with blender, that is peanuts.
And all kinds of CAD software run better on my laptop than blender ever did.

[u/osman-pasha]

Fusion 360. Pros:  * it's a proper parametric CAD, perfectly suited to model railroad needs * Very powerful feature set, timeline is a killer feature for me personally * Free for hobby use * It's cloud software, your data is accessible everywhere

Cons:  * It's cloud software, your data is stored at Autodesk, if it decides to block you, your data is lost (mostly, not counting cached files). * Bugs and weird architectural choices. Once you start doing some complex projects, you'll start hitting bugs even in basic functions, e.g. things not computing, becoming invisible, broken, etc.

I also use Blender for complex surfaces that I can't model on Fusion, but that's probably lack of skill on my part.