Unable to create form. Swept blend in conceptual mass.

[erik.eriksson.241829]

Hi,

I've tried to search for this question a while now, but havent found anything so I'm creating a new thread for this one.

I'm trying to create a swept blend using a combination of three point curves and straight lines as the path and just 2 straight lines in an angle as the profile sweeping to another 2 straight lines (with another angle and length).

All I get is the unable to create form error.

I've done a few investigations now to find out what the problem is.

Here is what I've come up with:

1. If I do the path as a spline it works.
2. If I have the correct path and, instead of just 2 lines as a profile, have a closed surface with the same shape as my 2 lines. It works, but only with one profile at a time (thus making it just a sweep), but the 2 profiles work individually.

My path is a reference line and I've made sure I'm using the correct work plane when I draw my profiles. I've also made sure that when I transfer from the 3-point-curve to the straight line the straight line tangents the curve. However this shoulnd be a problem, right? Because if it didnt there would be a corner in the profile?

Does anyone have any idea as to what I'm doing wrong.

Please help me, Im going nuts.

/Erik

[Dimitri Harvalias]

Welcome to the forums Erik.

A swept blend can only happen on a path that consists of single segment path. If you need the blend to change directions or planes you'll need to create it in pieces.

[erik.eriksson.241829]

Thank you!

Oh I see... That makes alot of sense.

One would think that it wouldnt be to difficult to implement that functionality.
Oh well... I'll have to do it the hard way... =)

By the way, do you know how far you can push the components in the conceptual mass environment.
We are looking into creating a curved facade with the conceptual mass environment and applying a pattern to this. Do you think Revit can produce the information in terms of drawings and schedules for a detailed design? I guess we'll have to dig into the API, but thats ok.
I mean its probably called conceptual mass for a reason...

Thanks

Erik

[Scott D Davis]

In the Conceptual Mass environment, you should be able to create a form that has multiple path segments and multiple profiles. In the family editor environment (doors, windows, generic models, etc) you are limited to a single segment path as Dimitri says.

Can you post an image of what you are trying to create?

(Edit: Just tested this myself and it's not letting me make a blend. Only a sweep, using 3 line segments and a spline. I will look into this)

[erik.eriksson.241829]

Hi again,

I'm now trying to make the shape out of 5 different paths with different profiles, which will be tricky, but worth it if it works.

However, I've run into trouble again, basically my profile is, again, is 2 connected straight lines, connected with different angles. See the attached file.

I'm trying to controll the angles of the reference lines with parameters and it works until I create form from the reference lines. Then a change in angles gives me a constraints error. Isn't it possible to change the angles of the shape with reference lines once you've created a shape?
If this doesnt work, I'm getting out ideas.

/Erik

Edit: It doesnt work using parameters, however, it works when I select a reference line and just alter the angle. What can cause this?
Second edit: It seems to work with parameters, but it appears to be very sensitive and generate errors without reason. When I try to assign a parameter it give the following error message "Revit has experienced an unexpected error. The operation has been cancelled to protect your project from corruption."

[erik.eriksson.241829]

Allright, I was able to fix it, I had to use the main workplane instead of planes from reference points I created.
Now I have a new issue, I want to use the lenght parameter in the reference lines to control other parameters. I can just create dimensions for the straight lines, but for the curved lines I need to use the radius of the curve and the angle. This creates alot of extra work when the length is right there in the reference line object.

Is there any way to use that parameter in formulas?