So this might be a little bit off topic, but I have some good experiences on this forum, so I’ll ask here anyway.
For my job, we use our 3D models from Rhino and manufacture them in a much larger scale in styrofoam.
The problem is that most models looks really smooth and rounded in Rendered mode. But when you get a look at them in Wireframe mode, most models will show a lot of big individual Meshed faces, with an overall much more “sharp” look, which we need to manually sand down to get a more smooth result.
Obviously the wireframe view represents the more accurate look of the model, so our end result in styrofoam will also show all the same Mesh faces in real life.
Is there some kind of smoothing going on in rendered mode? Or is it just a visual illusion. And maybe most importantly, is there a way to make models smoother/rounder?
For milling or 3D printing via meshes, smaller mesh faces will give you a “smoother” result closer to your NURBS surfaces. This can be controlled via the Doc Properties Mesh setting for the display and in the Mesh or Export commands for exportation/mesh creation.
using subdivisions will help you IF you are left with the mesh and have no NURBS to start with. there is a plugin called weaverbird which uses a smoothing called Catmull-Clark which works for both rhino and grasshopper. it will increase the polygon amount thus the file size of course. but he process itself is just a matter of a minute work. just be careful if there are hard edges which you want to keep, you may have to increase the polygon amount at those spots manually before using this tool to avoid too much smoothing.
Your physical product is probably fine if made well with NURBS. Those surfaces are inherently “smooth”. If you are seeing facets in your CNC milled or 3D printed physical models, then the person/company who is programming the CNC or translating your forms into mesh is not using fine enough settings.
Well, we buy our models on TurboSquid or similar websites. So there’s no real way of knowing how they were made and how they were exported. Most of the time there’s only a screenshot of the wiremesh model to go on to determine the quality of the model.
Usually the bought model comes in many different filetypes. Would you think there is any quality difference between filetypes or any other reason to pick one filetype over another? For example last model we bought came in: 3DS, C4D, FBX, MAX, MAYA and OBJ filetypes.
Well if you’re doing that, then odds are they were made as mesh models in the first place, and not designed to be built, so…yeah don’t expect them to be any good.
File type is almost meaningless if you are just getting mesh objects in the transaction. File type is just a container of different entities. Polycount is the critical value you need in order to assess your purchased models. Higher usually = smoother, but not always (for example, linear sub-d of a triangular face just creates more flat faces on the same plane, doing nothing for smoothness quality).
Unfortunately not super easy to find higher poly models on Turbosquid, but when checking a file’s page, the lower right corner has a 3d Model Specs showing polygon count. In general anything under a million is not going to work for production unless its a fairly simple shape, or depending on the final size of your object.
A 3dsmax file could contain both a proper NURBs and a low or high poly mesh; an obj could contain a low or high poly mesh.
Another solution for dealing with low poly meshes is Meshmixer. It’s free from evil Autodesk, but is incredibly powerful for a few key tasks in the production world. Runs on win and apple, works in real world units, has a simple interface. Using the right settings in remesh and smooth, one can fairly readily remesh a low poly mesh with a clean set of triangles for stl or obj export. I’ve had success using it to work on multi-million tri meshes. It’s a memory hog and a little buggy at times, but I’ve used it for various production projects for the past year or so.
Many other tools out there for upsampling low poly meshes. Zbrush is a good one, possibly overkill for you but deals with highpoly models incredibly well.
ZBrush Core is a stripped down version that might be ideal for simon9’s application. Pretty affordable ($179 US) compared to the full ZBrush program. Lots of ways to improve surfaces and enhance edges…
