About technical product design in Rhino vs zBrush vs Autodesk Inventor

rhino

#1

I wanted to ask about the relative strengths and weaknesses of doing technical product design (e.g. for an electric appliance) in Rhino vs zBrush vs Autodesk Inventor.

Understandably there probably are not a lot of people with experience in all three of these. I have very little experience in any of them but wanted to have an idea of what possible drawbacks there could be in choosing one over another.

For example I heard that one of the strengths of Rhino is the accuracy but a weakness might be that making changes later might be more complicated because of it being a NURBS based tool. Is this correct?


(Chris Kuether ) #2

Never used zbrush or inventor, but did use autocad and versacad. Rhino is far easier to use, accuracy unsurpassed, revision straightforward,


#3

Well the three products are for completely different things, aimed at totally different markets, they’re not really relevant to compare. Inventor is for Mechanical Design(i.e. making an engine,) Zbrush is for extremely organic modeling(i.e. character modeling,) and Rhino is for…well anything else.


#4

yea…although zBrush seems to be positioning themselves for work like Automotive Design and Autodesk does not seem to think that Inventor is solely for mechanical design work but also for things like product cases, looking at their use case examples.

Anyway I was not looking for a direct comparison between them but more like some information on the respective strengths and weaknesses. Sort of like what would cause a person to choose one over another.


#5

Mesh models cannot be used to make tooling, therefore ZBrush is unsuitable. Athough technically CNC machines could be programmed from a mesh model, the majority of CAM systems require nurbs.

I should add that its possible to convert a mesh to nurbs, but it complicates the process. T-Splines has been used to do this, but there are other options now.


#6

I haven’t used Z-Brush, but believe the advice you’ve been given so far is accurate. I’ve never heard of it being used for product design, which of course doesn’t mean it hasn’t, but as far as I am aware it is a polygon modeller most suitable for character modelling. Your link to their automotive stuff is interesting though.

Inventor is Autodesk’s Solidworks rival, if I recall correctly (I haven’t used Inventor for more than five minutes but have used Solidworks extensively). I’ll assume Inventor is similar to Solidworks.

If you need to build large assemblies of parts, or you need the power of parametric design for easy updates, Inventor/Solidworks is the way to go. Working this way imposes certain restrictions, but it can be very powerful if you know what you’re doing.

Rhino gives you more flexibility, and more direct control over every aspect of you model. If you are comfortable manually managing assemblies, and manually making updates to parts (parametric relationships can be a pain to manage), it works very well. I use it and haven’t felt the need to go back to Solidworks.

You can’t ignore the cost difference either - Rhino is fantastic value for money.


#7

Thank you all for your feedback. This all gives me a better idea of the overall suitability of these applications for this kind of technical design work.


#8

Rhino is suitable for models of boats, airplanes, and other curved objects that must be manufactured with high precision. Most of these objects are filleted polysurfaces. If you want to change them, you have to explode them, change them, and make new fillets. Minor changes take a few minutes. T-splines are easier to change and have smaller file size, but they are still more buggy than NURBS.

Inventor is precise, but not suitable for organic/curved shapes. It is well suited for machines made of large number of parts and parametric modelling. Parametric modelling means that changing one part automatically changes adjacent parts. It is suitable for simple shapes only.

ZBrush is not precise. It is perfect tool for sculptures of living things.

CAD software reviews: https://www.g2crowd.com/categories/cad


#9

I’m practicing both car body (NURBS) modelling and strictly mechanical design with Rhino (and Fusion 360 in parallel) and regarding mechanical design (surprise, surprise) I find myself repeatedly returning back to drawing on the Rhino model. Perhaps because the geometry for my mechanical models are fairly complex.

I’m not very experienced with either Rhino or Fusion 360 (least experienced with Fusion 360) but in general Rhino is “straight forward”, despite the not-so-sofisticated UI. Rhino simply does the job.

After a couple of month of training, have come to the conclusion that Rhino is underestimated, and it’s even useful as a tool for mechanical design. (especially if enhanced just a little bit more, as described below).

Although Rhino not supporting parametric design (as described in the previous post) the very approach to drawing is is intuitive, in the meaning straight forward - You draw the way you think about the geometry, whereas specialized tools like Fusion 360 takes a special drawing paradigm before you get anything done. If you can live without parametric design, Rhino is the Swiss-knife of choice also for mechanical design.

RHINO FOR MECHANICS

#1. One thing that Rhino should be enhanced with is to be able to scale (or resize) dimensions of existing objects in a similar way as Fusion 360. That is, point at a circle, get the radius/diameter presented, and an edit box where to enter a new absolute value, as opposed to a percent value for scaling.

#2. And enhanced fillets.

Having those two concepts added/enhanced would lift Rhino to another level even for mechanical design (parametric has it’s benefits, but you can live without it).

// Rolf


(Wim Dekeyser) #10

Have you tried the ModifyRadius command?


#11

Doesn’t seem to work on Solids. I should have mentioned that, since in mechanical design solids are more or less implied.

But thanks for this hint, I actually didn’t know I could modify curves, which is better than nothing.

// Rolf


#12

boxedit might do what your looking


#13

Yess! That actually does what I want. In most cases at least.

I could even shrink the diameter of a hole in a solid, without affecting the outer diameter (by CTRL-Selecting only the inner surface).

Many thanks!

// Rolf


#14

I agree; having come from an autodesk parametric environment; content-aware direct entry/adjustment of dimensional data is a big part of my workflow…

I’ll try the methods listed above…


#15

You could also try Pascal’s ScaleByAdd script, which allows you to scale 1/2/3D by picking a reference point and then typing a distance to add (or subtract) in a chosen direction. A very useful tool. I’ve never tried it in combination with CTRL-selecting surfaces within a polysurface. I’ll have to try it. If it works, it would be a neat way of changing the diameter of holes in solids.


#16

I just did that, with BoxEdit. CTRL-select the surface of the hole, type BoxEdit, then type in X and Y diameter, and off you go.

// Rolf


#17

Zbrush is a sculptors tool, best for organics and highly detailed geometry, Zbrush cannot create models that will be used for more technical aspects where exact mechanical tolerances are required…there is not even a measurement tool in the software…

Rhino is my go-to for all hard surface modeling or any model that needs to be mechanically accurate.

I have not used inventor so I cannot comment on that.