BlendSrf bad output


BlendSrf does not work correct at all, regardless if with or without history.
This was made with G2:

In V5 it works ok.
See file attached.

CP_BlendSrf_Fail.3dm (76.2 KB)

It’s in Youtrack list

Hi Charles - thanks, yeah, we’ve noticed a couple of cases like this - for now, it cleans up if you click Add Shapes and then snap to the four points that show up.


Hi Pascal,

add shapes did the trick.
What comes out is not so very G2ish:


Hi Charles - I guess we might need to make the simple sweep optional… Even MatchSrf does not get this any better without adding a few knots with Refine.


Maybe when the blend can be a simple surface, we should add in all of the shapes at rail edit points right from the start.

I vote for this, but I hope there will be an option that can enable/disable this automation. Users can then use the MatchSrf command to improve continuity after the simplest simple blend has been created.

Hi Kelvin - if the Blend is simple, adding the edit point shapes does not make it more complex, if that is what you meant, but might be a little hard to explain to users - one reason we decided not to do this in the first round.

All ‘edit point’ shapes added:


I was not aware of this. Thanks for pointing this out.

If the shapes are not automatically added, users that are not aware of the new simple blend feature, or don’t know how it works, would think it’s a bug of continuity calculation.

I thought exactly this…

While we are at the blend:
When the preview is active, it would be really handy to have access to the analysis tools.
I know the preview is not an object that we could add, but perhaps there is a simple way to make it possible?


I have a few other users that have requested for this

This wish is natural, I remember I wished this back in V2 days…

Such a feature would help a lot to produce very good blends.
Same applies to several other surfacing tools.

1 Like

Now with 6.0.15169.5041, another problem is there:
After adding a shape, undo doesn’t work for this new shape.

And a question:
How to remove the automatically added shapes?
And a user placed shape?


I think the shape adding undo is pretty well fixed now. Let me know if not.

As far as removing the automatically added shapes -
Those are added when the blend is a simple surface between compatible rails, and there is one at each edit point of the surface. Not adding those was what caused the anguish about blends that weren’t smooth when the surface was simple and therefore not fit. If I don’t add them, that will happen to some extent in all but the very simplest geometry.

Why do you want to remove them? Is it for some modeling reason, or more a matter of pointing out a consistency problem in the interface?
I can imagine that having more handles makes it harder to adjust the bulge along a whole edge. If that’s it, maybe it should be handled with locked sliders like in MatchSrf or something.
I don’t think of another reason right now.

I think that if it would really be good to be able to remove them, I’ll have to add a Remove Shapes mode and ask you to pick which ones to remove.

About the analysis modes being active, I hope to get that done on a few commands before too long.


For modeling reasons.

Which sliders?

That would be good.
As it is now, we can only undo the last user added shape.
It can also be we want to remove the 3rd added shape, while 4th to 7th shall remain.

That is very good news.


Sorry, I don’t know what I was thinking about.
Forget that part