Filleted edges don't show in hidden line rendering.

[line-weight]

I am quite commonly coming up against this and don't know if there's any way around it.

 

These two objects are the same except that the right hand one has all of its stepped edges filleted.

 

 

Looking at these in elevation, with hidden line rendering, produces this:

 

 

 

On the right hand elevation, only the bottom step shows.

 

I understand why this is the result: the fillets meet the faces at a tangent and so, technically, there is no edge to draw. However, in real life, if the filleted edge has a small radius compared to the overall object, generally you want to see some sort of line in that location. When I used to draw by hand, I'd decide whether a line was wanted on a case by case basis and sometimes might draw a kind of dashed line to indicate it wasn't a hard edge.

 

Fiddling with the smoothing angle has no effect. Again, I understand why. The fillets meet at a true tangent so there is no edge, not even a 0.00001 degrees change in angle.

 

It would be good if hidden line could deal with this better, although I can see it would be hard to implement to cover all cases including those where you actually don't want a line. What happens in other 3d modelling programs?

 

 

 

 

fillets.vwx

[VIRTUALENVIRONS]

I am using VW18 in this office, so I did not download your file.  I recreated it as closely as I could.  I seem to get the desired result in VW 2018.  The 3D image (left) is hidden line and the frontal is "convert to lines".

 

What happens if you "convert to lines" to produce a 2D object only.

[VIRTUALENVIRONS]

My apologies, forgot screenshot

[line-weight]

I don't quite understand what we are looking at there - are these viewports on a sheet layer?

I've attached a VW2018 version of my file, you can see how things come out on the sheet layer.

 

In any case what your image shows isn't really what I'm after - I would just want one line per filleted edge, not two.

 

Anything that involves converting a viewport to lines is out of the question because viewports need to remain updateable.

 

 

fillets v2018.vwx

Edited November 1, 2023 by line-weight

[Pat Stanford]

Check the Smoothing Angle on your render settings. That controls what kind of lines are shown.

 

[VIRTUALENVIRONS]

1 hour ago, line-weight said:

I don't quite understand what we are looking at there - are these viewports on a sheet layer?

I don't really know how to create a viewport or what a sheet layer is, so I will bow out of this thread.

 

Although I use Designer, Fundamentals would probably be as good, except for creating a site model.

 

I was looking at this from a purely technical illustration.  I am/was a technical/patent illustrator in both pen/ink and Vectorworks.

 

 

[line-weight]

39 minutes ago, Pat Stanford said:

Check the Smoothing Angle on your render settings. That controls what kind of lines are shown.

 

 

As far as I know the smoothing angle has no effect in the scenario I describe, for the reasons described in my OP. If you download the example file and look at the sheet layer you will see.

 

What you have shown above, is this wireframe or hidden line? If your Viewport 2 is hidden line, and your edges are true fillets then you are getting a different result from me, in that for horizontal steps you get two lines where I get one.

 

Also note in your example, all the steps have a horizontal surface meaning you are looking directly along them in elevational view. In my example, the one horizontal step generates a line (as I'd expect) but it also includes sloped steps which don't.

 

 

[line-weight]

A kind-of related issue:

 

It would also be good if hidden-line elevational views were somehow clever enough to reduce the number of very closely spaced parallel lines where they occur.

 

There is often detail which is useful to show at large scale, relating to things like window frames, but not at smaller scale. There might (in elevation) be several parallel lines describing different elements of a window frame - they might be say 10 or 15mm apart. But once you are looking at these on a 1:50 or 1:100 scale elevation, they are virtually drawn on top of each other and it then creates a somewhat ugly bunch of lines that can also be mistaken for a single line in heavier lineweight. This is another thing that can be dealt with by the draughtsperson's judgement when drawing manually but not so much when you are extracting from a 3d model.

 

I doubt this is easy to deal with so I don't expect to see it solved soon - just a thought.

[Tom W.]

This is where 2D components for symbols comes in + customising their detail levels

[line-weight]

1 minute ago, Tom W. said:

This is where 2D components for symbols comes in + customising their detail levels

Yes, but essentially means reverting to a manual drawing process, at least partly.

[Tom W.]

Yes but this is always the trade off: the time it takes to do something but get the exact results you want against having VW do something automatically but the results being unsatisfactory. Auto-Hybrid automatically creates a Top/Plan representation of a 3D object for you but I rarely use it because you have little control over which lines are represented + which aren't. With Hybrid symbols yes it can take a little bit of time to set them up but once it's done it's done + you have complete control over what's displayed. The 'Generate 2D from 3D component...' command makes it quicker.

[bcd]

I think it's just an enhancement request for the Hidden Line. To indicate curved edges with greater/lesser/no degree of linework. Oldschool but very effective.

 

[line-weight]

4 minutes ago, bcd said:

I think it's just an enhancement request for the Hidden Line. To indicate curved edges with greater/lesser/no degree of linework. Oldschool but very effective.

 

 

What have you posted an image of, exactly? That is displaying the curved edges differently from what I get in a hidden line viewport.

[EAlexander]

I think he drew that as a 2D example of what it could/should/would look like if you could control how it displayed.  Kind of like how we used to draw those things with a pencil.

 

I agree with your original post/thought - It would be nice to have better graphic control over this.  I do my filleting as late as possible or not at all to avoid this kind of problem and keep the lines crisp.  Once I move to CInema4d, I round over edges there.  Corona renderer lets you round over edges via material which is great, but I digress....  It would be great for hidden line to average the radius if under XX" or to space evenly for larger curves.

Edited November 2, 2023 by EAlexander

[bcd]

33 minutes ago, line-weight said:

What have you posted an image of, exactly? That is displaying the curved edges differently from what I get in a hidden line viewport.

It's a hidden line rendering of an extrude, with the corners clipped by a regular 18 sided polygon. It represents how, yes, we would illustrate a curved edge like this with a pencil.

I think this effect would add alot of versatility to Hidden Line Renderings for exactly your case.

[line-weight]

Ah, I see. Thanks.

[VIRTUALENVIRONS]

Gentlemen, I bowed out of this early, but it seems that it has come around back to skill sets.  I did look at Line Weights problem and it appears to be the result of using Polyline.  I never use Polyline, never had good results.  

During the years 6 BMC (six years before MiniCad) I made all my mechanical assembly dwg's. in 3D by hand, ellipse templates, pen and ink, French curves, etc.  Below is an example, the image is forty years old.  These are not ass'y dwg's.

 

There are and have been a set of fairly rigid guidelines on technical dwg's. for a few centuries now.  Rigid in patent, looser in technical.  But the guidelines are strict on Line Weight....not our Line-weight, but the thickness of lines.  The second image explains.

 

 

[line-weight]

VW does seem to render it slightly differently in elevation if I build it from a solid that I then apply 3d fillets to.

 

Draws two lines if I have a smoothing angle of 1 degree, no lines if I have a smoothing angle of 5 degrees.

 

So, still draws it "wrong" but in a different way.

 

The kind of drawing conventions shown in @VIRTUALENVIRONS post above are what I'd ideally like VW to use (or be able to use).

[bcd]

Maybe the new option could be 'facet curves for HLR'

Edited November 3, 2023 by bcd