Rhino - surfaces through curves and points

[DCockey]

Incorrect claims have been made that it is difficult or impossible in Rhino to create surfaces which pass exactly through input curves or points.

Rhino has several commands which can create surfaces which pass exactly through input curves. Each command works with a specific arrangement of input curves. Some of these commands have options to rebuild the input curves within a tolerance to simplify the resulting surfaces. If these options are not selected the output surfaces will pass exactly through the input curves. If the input curves were created from curves which pass exactly through sets of input points (see Rhino - exact curve through points is easy and quick https://www.boatdesign.net/threads/rhino-exact-curve-through-points-is-easy-and-quick.63897/) then the surfaces will pass directly throught the input points to the curves.

Rhino commands which create surfaces that pass exactly through input curves include:

EdgeSrf Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/edgesrf.htm

Loft Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/loft.htm

Sweep1 Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/sweep1.htm

Sweep2 Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/sweep2.htm

ExtrudeCrv Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/extrudecrv.htm

ExtrudeCrfAlongCrv Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/extrudecrvalongcrv.htm

ExtrudeCrvTapered Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/extrudecrvtapered.htm

ExtrudeCrvToPoint Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/extrudecrvtopoint.htm

PlanarSrf Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/planarsrf.htm

Revolve Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/revolve.htm

RailRevolve Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/railrevolve.htm

Rhino has several commands which create surfaces directly from input points, and the resulting surfaces pass directly through the input points.

SrfPt creates a surface between 3 or 4 corner points: Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/srfpt.htm

SrfPtGrid creates a surface which passes directly through a grid of points. Each row of the grid has to have the same number of points, and each column of the grid has to have the same number of points. Rhinoceros Help http://docs.mcneel.com/rhino/6/help/en-us/index.htm#commands/srfptgrid.htm

 

[pafurijaz]

Is useless these series of examples that show only simple surface made by two boundary edges or extrusion with one or two path or the revolving surfaces, that as I already said is simple the thing complex come out when you have more than two I know Rhino and NURBS, the problem is with model like those below to predict the surface.

 

[pafurijaz]

Here what I talk about this is a software for really control the final results, and it cost over $8000 for a license.

an other one

You can make that with Rhino? Yes but is very hard works with a lot plane projections and many blended surface made by tiny patch made by simplest surface, but is not required this precision for most of modelling, in fact rhino is mostly used in Architecture where there is planar edges, for ships or other advanced yacht design the company use CATIA, NX or Alias Design for productions Rhino is mid range software not for high end solutions. But this is possible if accept a compromise.

And here a professional that where you can see the difference between Class A Surface programs and Rhino, Moi3D and all other mid range Nurbs modellers
class A surfacing https://www.youtube.com/channel/UChgD5KIJoL2cunXvU6XOfJQ

 

[DCockey]

And here a professional that where you can see the difference between Class A Surface programs and Rhino, Moi3D and all other mid range Nurbs modellers
class A surfacing https://www.youtube.com/channel/UChgD5KIJoL2cunXvU6XOfJQ

Pafurijaz, which video has anything about Rhino?

 

[pafurijaz]

Pafurijaz, which video has anything about Rhino?

None of these because as I said with Rhino it is not possible to create complex surfaces with predictions because they are interpolated to give a smooth surface, but only the basic examples such as you linked in your post, these are examples, what they are and what is meant by surface control, that's all, it's a purely theoretical discourse which is not required by most hulls, only when working on complex structures is it necessary to use certain programs where the cut CNC plates must perfectly match, often the small to medium sized shipyards rely on on-site corrections, but this is not possible when you have to work with iron plates more than 2cm thick. In fact, here we speak on a theoretical level, and many shipyards employ skilled labor. Of course, on small boats the error can be handled by the workers.

 

[pafurijaz]

In this video you can see what I mean when I say control the boundary of a final surface, the spline are far from the surfaces but is OK because is accepted compromise, but if you design hull from from a linesplan with this constraint , sure you need to re-edit to match the original project but for a new hull you have the opportunity to work with the final result. and then export to others CAD that make plate from this new shape, rhino is a great software, but the control of surface is the most hardest work even with advanced software that require a lot of time.

 

[Ad Hoc]

...e and what is meant by surface control, that's all, it's a purely theoretical discourse which is not required by most hulls, only when working on complex structures is it necessary to use certain programs where the cut CNC plates must perfectly match,....

It seems to me you're discussing 2 very separate issues here.

CNC cut parts are for metal boats.
Metal boats do not have complex shapes. There are many reasons why - but ostensibly it is because of the difficulty of creating a complex shape with a sheet of plate.
Can it be done - yes- but it takes up a huge amount of time effort skill and ultimately money. Each plate ends up smaller and smaller to be able to form such shapes.
In addition it weakens the mechanical properties from the plate being rolled into 2 different planes.

So, as you say, what you're discussing is a pure theoretical point of view.

Which in the context of shipbuilding - and hence this thread's Subject - not relevant.

For ref, we use Rhino and very successfully on a range of vessel size and types. The issues you raise, we do not encounter, because the user understands the end objective - that being the plate work (from the shape/surface being created) must be formed with a simple roller. Thus all the Lines Plans are created from simple conical and other shapes which are easily developed.

The car you show - that is not a a simple easily developed shape - and that's the point.
Cars are not boats..

Since can your software produce a set of limiting KG data?... I suspect the answer is no.

Personally i'm not fussed about the nuances of the software, so long as it can do what I require/need. And Rhino does that - in spades, which is very cost effect too.
So I select the right tool for the job. Rhino is that tool.

Just as when I do my FEA, I use a dedicated FEM programme. Does that mean Rhino is unsuitable, no, not at all - just use the right too, for the job.
And are there many different types of FEM programmes, yes.... which is best, is a combination of personal choice and understanding if it delivers what you want/need.
No different to a software programme producing a set of Lines for build... and thus it seems your personal preference is not Rhino - good for you.

 

[DCockey]

Lots of real world products including boats designed using Rhino shown on this thread in the Rhino forum: Real life product design examples made in Rhino https://discourse.mcneel.com/t/real-life-product-design-examples-made-in-rhino/60157
And towards the bottom for those interested there is considerable discussion of using Rhino for automotive "Class A" type of surfacing. My summary of that discussion is Class A surfacing methodology as traditionally done in the auto industry is simpler with some much more expansive software, but the same quality of surfaces can be achieved using Rhino.

 

[DCockey]

An example of complex, high quality surfaces created using Rhino and which had to accurately match existing surfaces and structure of the donor vehicle:
Real life product design examples made in Rhino https://discourse.mcneel.com/t/real-life-product-design-examples-made-in-rhino/60157/284

From the post linked above:

The concept model was done by someone else, but all that was provided was a sub-d mesh model which did not really fit the actual car geometry, so a lot of the job involved not just technical surfacing, but doing lots of re-interpreting that art to fit the donor cars. Everything forward of the doors is totally new. The rear bumper and decklid are of course heavily modified as well. ​

Video about the project with discussion of the exterior design starting at 7:35:

Images from the manufacturers website Super Duty 455 by Trans Am Depot : 1000 Horsepower 1046 Torque https://transamdepot.com/superduty/ :

 

[pafurijaz]

Sorry but not what I said if you read I said that it can be done, and you can show what you want to me.. but the reality is an other. Even whit Blender here a project of half million car design with Blender you can do that thing, I understand you are fine with rhino and for me is OK the point is the surface predictions trough specific spline what whit this post started and the first car made with Rhino was the Saleen S7 I used Rhino for work and the first time in 2001 and I bought a license int the same year, and Now I use Moi3D the same.
But the point is an other.. I give up

Some car made with Blender. and you can construct that and convert to Nurbs but the point in an other!


An half million dollars Cars under development! With Blender.

 

[Ad Hoc]

...An half million dollars Cars under development! With Blender.

Don't see any Lines Plans for boats?

 

[pafurijaz]

Don't see any Lines Plans for boats?

Seriously? https://www.boatdesign.net/attachments/istantanea_2020-05-20_12-57-30-png.156769/

 

[Ad Hoc]

That is not a Lines Plan.. it is just a rendering!

So, is that just a fancy looking 3D rendering, for show... or is it for an actual real boat?

 

[pafurijaz]

made totally in Blender even the sheet metal development

 

[pafurijaz]

an other just for fun