Can anyone recommend good (light use) CAD / 3D modelling software?

evilquoll · 30 May 2017, 06:32 AM

I have tried to model various polyhedra (in Wavefront Object format, usually using Microsoft Excel to do the calculations and Notepad++ to write the file), and am having problems.

Although my simpler models work in TinkerCAD (a free online lightweight CAD program from Autodesk), it doesn't recognise the more complicated ones (such as the rhombic dodecahedron), nor does it allow more than one material to be applied to a model (my tetrahedron model comes out as solid red, although the file specifies that each face is a different colour).

3D Builder (included with Windows 10) renders my models in all their glory, but annoyingly it often says that the model has an error -- but doesn't say what the error is, so that I can go back to the file and correct it. (I suspect that the problem is that one or more of the faces are described in the clockwise direction, so that the normal points inward instead of outward as it should.)

Both those programs are basically "toy" CAD programs; they give a taste of what 3D modelling can do, but they're not really suitable for serious design work, even at the basic level. I doubt that I'm the only one who feels the need for a lightweight modelling program; AutoCAD and the like aren't the answer, because they're massive overkill for what I want, and in any case they start at hundreds of pounds (one level of AutoCAD I saw listed was over £2,000

). The situation is basically like a photography enthusiast being limited to choosing between cheap disposable cameras from the supermarket, or Sinar plate cameras (those are bulky, and very expensive, professional cameras which directly produce a high-quality 5"x7" or larger negative). Surely there must be a CAD equivalent of the Pentax; neither lacking in features, nor overburdened with them, and at a price point which doesn't require mortgaging all your worldly goods?

And before anyone mentions it, I know about POV-Ray; that's a good rendering program, but I don't know of anything in it which helps create the models in the first place.

evilquoll · 31 May 2017, 09:26 PM

I think that one problem with 3D Builder, as revealed by its so-called "wireframe" view, is that it's geared more towards .STL format, in which all faces must be triangles, hence regards non-triangular faces as "invalid", even though they're perfectly valid in other formats!

(3D Builder "corrects" my dodecahedron model to having seven(!) triangles per face, although three would have been sufficient without having to create any new vertices.) (And in any case, STL supports only one material (colour) per design, so my dodecahedron couldn't be correctly exported to.STL without losing the face detail; at least one website out there regards .STL as obsolescent if not obsolete.)

mister · 16 Jun 2017, 02:04 AM

https://www.blender.org/

30 May 2017, 06:32 AM	#1
evilquoll Member Join Date: May 2017 Location: Emergency temporary account of ROBERT.BAK Posts: 36	Can anyone recommend good (light use) CAD / 3D modelling software? I have tried to model various polyhedra (in Wavefront Object format, usually using Microsoft Excel to do the calculations and Notepad++ to write the file), and am having problems. Although my simpler models work in TinkerCAD (a free online lightweight CAD program from Autodesk), it doesn't recognise the more complicated ones (such as the rhombic dodecahedron), nor does it allow more than one material to be applied to a model (my tetrahedron model comes out as solid red, although the file specifies that each face is a different colour). 3D Builder (included with Windows 10) renders my models in all their glory, but annoyingly it often says that the model has an error -- but doesn't say what the error is, so that I can go back to the file and correct it. (I suspect that the problem is that one or more of the faces are described in the clockwise direction, so that the normal points inward instead of outward as it should.) Both those programs are basically "toy" CAD programs; they give a taste of what 3D modelling can do, but they're not really suitable for serious design work, even at the basic level. I doubt that I'm the only one who feels the need for a lightweight modelling program; AutoCAD and the like aren't the answer, because they're massive overkill for what I want, and in any case they start at hundreds of pounds (one level of AutoCAD I saw listed was over £2,000). The situation is basically like a photography enthusiast being limited to choosing between cheap disposable cameras from the supermarket, or Sinar plate cameras (those are bulky, and very expensive, professional cameras which directly produce a high-quality 5"x7" or larger negative). Surely there must be a CAD equivalent of the Pentax; neither lacking in features, nor overburdened with them, and at a price point which doesn't require mortgaging all your worldly goods? And before anyone mentions it, I know about POV-Ray; that's a good rendering program, but I don't know of anything in it which helps create the models in the first place.

31 May 2017, 09:26 PM	#2
evilquoll Member Join Date: May 2017 Location: Emergency temporary account of ROBERT.BAK Posts: 36	I think that one problem with 3D Builder, as revealed by its so-called "wireframe" view, is that it's geared more towards .STL format, in which all faces must be triangles, hence regards non-triangular faces as "invalid", even though they're perfectly valid in other formats! (3D Builder "corrects" my dodecahedron model to having seven(!) triangles per face, although three would have been sufficient without having to create any new vertices.) (And in any case, STL supports only one material (colour) per design, so my dodecahedron couldn't be correctly exported to.STL without losing the face detail; at least one website out there regards .STL as obsolescent if not obsolete.)

16 Jun 2017, 02:04 AM	#3
mister Essential Contributor Join Date: Jun 2002 Posts: 387	https://www.blender.org/