Project command with Cplane to view unexpected result

HI

I am making a reverse engineering , something i make every once in a while but i am now stuck to a point

i am tryng to project a set of line on a mesh to obtain the curves for a network surface.
In order to project i set 3D view to a generic position ( the desired one ) , i then set CPlane to “view” and launch Project command thus expecting that , the projected crv would generate a crv directly on the mesh and that the curve created would be overlapping the line within reference to the generic view.

this is not was is happening though , the generated curves seems to be using a different projection CPlane

how can i get line the curve projected directly under the “father” line or crv within reference to the gering perspective view ?

thanks, cheers

You can specify a custom projection direction in Project (command line option Direction=Custom) - no need to change the CPlane or view.

@cloudsvisitor77 Are you confusing the Pull and Project commands?

Pull and Project are two different commands. Pull pulls the objects to the selected surface in the direction locally normal to the surface. The direction varies across the surface if the surface is not planar. The construction plane orientation does not affect Pull.

Project projects the object onto the surface in a single direction.

Only in Rhino 6 and later. Rhino 5 and earlier only project normal to the active construction plane.

Yep, since I didn’t see any mention of version, I assumed current…

let me apologize , i tried both commands with similar result but i was refering to project since the pull does not ( correct if i am wrong ) depend on cplane used

I hav enow corrected the post title. thanks

i see what you mean but this is not what i want and its time consuming
i just want to project the line over the mesh within respect to the generic 3D view…this is way more easy , its not necessary to define the normal axes everytime because it should be defined by the view.

what i cannot undestand is why the line is not overlapping the projected crv

i wonder if this could be a matter of perspective view setup

hold on , latest news : after playin with view set up and so on it now seems to work. not usre either what fixed it , point is that now i cannot replicate the problem…smeel of bug to be honest , if i will ever find out something more i will update you guys through this post

thanks anyway for your answers

OK, I was under the impression that you wanted to project according to the current view’s CPlane and not according to the current view’s camera–>target direction.

Maybe this script will do something for you then?

ProjectCrvsInViewDirection.py (1.3 KB)

Note that projections in the view direction in a perspective projection viewport are not necessarily going to be predictable due to the perspective ‘distortion’.

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It’s not been the question, but I honestly would rather try to “quadremesh” your mesh, ToSubD and then toNurbs. This might be veeeery time saving.

ah, no, rhino5…

To find the apparent intersection as seen in a perspective view:

Create a surface using ExtrudeCrvToPoint from the curve to a point located at the camera. Someone else may have a good way to create a point at the camera location. Essentially “ExtrudeCrvToCamera” is needed.

Intersect the extruded to a point surface and the target surface.

Delete the extruded to a point surface.

In Rhino 6 and later the “View” direction option in Project is the direction parallel to the centerline direction of the view/camera.

If you are setting the CPlane to the view and the view is not a parallel one, the projection will not be ‘on top’ of the original, visually.

-Pascal

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My suggested method above will put the projection in the locations seen in a perspective view.

This is what I meant - no idea if that might be what was throwing the OP, possibly-

-Pascal

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