Problem exporting Rhino curves to 3dsMax

Replies to This Discussion

Permalink Reply by Leo on July 30, 2013 at 7:19am

Hello Dave,

some ideas:

-have you tried rebuild the curve in GH  (rebuild curve component, un curve>utilities). You can set the number of points.

-have you tried rebuild the curve in Rhino (Edit, Rebuild). Again, you can set the number of  points for rebuild. 

-In  case you export via dxf/dwg, the exporter let you choose a Export Scheme, and each scheme let you set the curve definition. 

-finally, in Max, you can try Normalize Spline modifier, and reduce the number of points of the curve. 

Permalink Reply by beardface00 on August 2, 2013 at 8:27am

Hey Leo,

Thanks for all the ideas, very much appreciated.

Within Rhino and Grasshopper I have pretty much complete control of the curves and their makeup and I'm very happy with these conditions.

As you mentioned in your 3rd dot point, I am trying to export via dxf/dwg or iges/igs or whatever other format that 3dsMax will accept and this is where I am encountering my problem with the control points/vertices multiplying exponentially once they are imported into 3dsMax.


I've previously exported the curves using dwg with various levels of success, and .igs imports them as nurbs curves, but this limits the Max modifiers I can apply to it

So effectively what I am after is the "Silver bullet" answer
- an export scheme from Rhino that manages to take into account both arcs and polylines, maintaining their millimetre perfect curvatures/trims/fillets etc, and also maintains their control point count. Unfortunately using normalise spline in max destroys the curves relative positions to one another.

My lines are perfect in rhino I just want to be able to use them in 3dsMax!!! (Not yelling at you, just the world in general)

If you or anyone else has another idea, I'm still chasing the answer!

Permalink Reply by Jonah Hawk on August 2, 2013 at 4:34pm

If you are only exporting shapes/splines/curves, Try exporting to Illustrator .ai.

If you are exporting surfaces, use .sat. It will come in to Max as Body objects, a parametric, rebuildable nurbs surface.

The shapes will come through as native Bezier curves. I'm sure they may not be exactly the same as rhino nurbs curves but you're losing that in translation anyway.

 

 

Permalink Reply by Jonah Hawk on August 2, 2013 at 6:23pm

by the way, if you are ultimately converting to EditableMesh, as in your image, you will end up with many vertices anyway, regardless of the number of vertices (control points) in the Max Splines. All Max Shapes (Max's equivalent term for Curves) have a Steps parameter in the Interpolation rollout of the base object. It determines how many sub segments there will be per segment, the curves between vertices.

 

Permalink Reply by Jonah Hawk on August 2, 2013 at 6:44pm

Here is a simple comparison of Rhino > AI > Max. again, this is not very scientific. I screen capped the rhino viewport, Exported as .ai, imported into Max and use the screen cap as a background.

 

 

Permalink Reply by beardface00 on August 3, 2013 at 9:29am

Thanks for the replies Jonah Hawk!

The .ai export method looks intriguing and could definitely prove to be useful. Not at my PC this weekend but will test on Monday.

My plan is to use the imported curves as editable splines, not editable meshes, as I don't want to collapse the modifier stack and lose the parametric elements of max (offsets, chamfers, bevels etc).

There are two ways in which i would like to use the curves
-The imported curves need to be useable by my colleagues who don't use or have access to rhino and will potentially be doing several variations on a design theme, but then have the modifier stack reapply the offsets, extrusions, materials IDs etc. Too many vertices along all the curves make this too inefficient on the large scale projects I'm currently working on (10 acres of parkland)

-The alternate method I'm using, is modelling everything in rhino, parkland, parkland borders, paving between grassed areas, lots of amorphous shapes with specific offsets (similar in style to this http://www.zaha-hadid.com/architecture/dongdaemun-design-park-plaza/).
Then I import this into max to extrude, shell, render etc.
This way unfortunately is not very parametric either, as it requires me to model each change in rhino, using GH where I can, but then exporting uneditable, non parametric geometry to 3dsMax.

One of the recurring issues I have is when curved lines are imported , each curve is treated individually according to the export settings and as a result, adjacent and completely touching curves are interpolated differently to one another due to their individual lengths and tangents, losing the exactness of the detail created in rhino.

Still keen for any advice on whether there is an answer to this problem? Or even a combination of answers.

Cheers,

Dave

Permalink Reply by Jonah Hawk on August 6, 2013 at 5:26pm

You will not be able to get the side by side, perfect curves as you have in Rhino. Max shapes have the step segments I describe above.

 

You can solve (most) of that adjacent curve gap issue by increasing the steps on those splines. (see note below regarding plugins)

I know you don't want to hear this, but for that scale, you don't really need that level of accuracy, do you? How big are the gaps? (just sayin') ;-)

 

Another workflow you might try is exporting as DWG and using Max's File Link Manager to import the lines/curves. As long as your modifiers are simplistic and are not dependent on subobject selections in the shapes/curves, you can make updates in rhino, export to the same dwg and your team can Reload the dwg from the Manage Links dialog. We do this with Revit/FBX.

 

On another note, look for the free Max plugin called HSpline. It is a modifier that lets you set the segmentation of shape objects as a modifier. It can be handy for controlling that segmentation in the modifier stack.

Interp. Spline is similar but it sets the Steps per segment.

 

Both are on plugins.de

 

 

Permalink Reply by Donald E Vance on August 6, 2013 at 7:20pm

If you have two shapes designed to fit perfectly together, and after exporting they are very slightly different. Why not just delete one and use the other in both situations?

If I remember correctly the .ai format will flatten your shapes into a 2d space, Which may be problematic for complex forms like what you linked. Its not the end of the world but you may have to do some thinking before exporting with it.

I always think of exporting and importing as a process unto itself, sometimes you have to prepare information to be exported and generally you have to clean it up after it is imported. This is especially true between software designed by different companies.

Permalink Reply by Beton on April 27, 2014 at 4:53am

its may an old topic. but maybe there is another way. More steps an I did´t try it but may it could work:

There is a Plugin for C4D called rhinoIO. With that you can OPEN Rhino files and they stay sync. So If you change something in rhino/gh and you save it, C4D is updating the geometry. I did that recently and it works like a charm, with textures and everything. May from there to 3ds works better?

Just a idea,

good luck