Background: I am an inexperienced user of CAD but have acquired Rhino 7 (Student version) and try now and then to do some training to improve my understanding of this tool.
For many years I have had RC modelling as a hobby, and like to build and fly model airplanes with a focus on scale appearance, meaning that there shall have existed a full scale aircraft with the corresponding general geometric outlines.
3-view drawings do normally constitute the source for the geometry. In earlier days this input was converted to manually drawn drawings to a chosen scale. Nowadays such 3-view drawings of course can be placed in the background of a CAD-S/W , for instance Rhino, and then by tracing in the CAD be created as a CAD model, and this approach also I have been playing with.
Question: Nowadays there exists on the web a large number of 3D models of different airplanes.
I have been thinking that by down-loading such models it should at least in theory be enabled the possibility to more or less automatically get hold of a much more complete description of the geometry.
When I look through such web sites, the first thing that shows is that the 3D model in question is available in “strange” file formats. However, in some instances the supplier offers file conversions to formats referenced to suppliers of 3D CAD engineering tools like AutoCad but also Rhino.
In the specific case I am interested in right now (see web address below), it is stated that
“file conversion to .3DM-Rhino (not solid)” is offered.
Q1: If I do acquire and download a 3D model in an acceptable file format, what will I be able to undertake with this model? I assume that I shall first download the model and store the file in a chosen catalogue, then start up Rhino and open up the file in question.
Will I be able to manage, rotate etc. the model as if I had constructed it myself from “the ground” in Rhino?
Q2: In my own design process I do edit the geometry substantially on detail level to simplify the build process. Will there be some allowance to change the geometry to some extent in the downloaded model, or will I instead be forced to create an own generated “twin” using the downloaded model as a non-editable source of geometry ?
Q3: Will I be able to make arbitrary section cuts in the downloaded model and project the cuts perpendicular to the cut ?
Q3: Which file formats of the 3D model aimed to be downloaded will be accepted by Rhino “without fuss” ?
Web address to Specific case of interest:
Thank you in advance for your viewpoints, suggestions and other comments
Owe
Owe, if you can get a model in STEP format, that works well. You will be able to do just about anything your skill set wants.There are tools such as Contour or Section that help in creating cross sections through a model. You can even intersect a model with a surface as a plane where you choose. As far as making modifications , that comes down to how much you can use the tools available and how to use them. Making changes sounds a lot like rebuilding.
There are people on this forum that are very talented in the aero world. Hope they can help.—-Mark
Thank you Mark very much for your response.
Does your answer mean that you actually would recommend a model in STEP rather than a model in this “.3DM-Rhino”, which is available in this case ?
I figured that this denoted format (“.3DM-Rhino”) would be the best one suited to handle in Rhino.
Maybe I should send a mail and ask if STEP is something they can deliver even if it doesn´t show on their website as an option.
But if I would choose a file conversion to “.3DM-Rhino”, what do you think I could do with that model in my Rhino 7 ? Open up, zoom, rotate, print out in different angles and scales ? But not generate cross sections ?
You mention that talented people in the aero world do act on this forum , but unfortunately they seem to be asleep .
Best Regards
OWE
Correct. .3dm format is prefered for import into Rhino when it is available. Mark probably did not notice that the model you linked to is available in .3dm format and so recommended Step format as a good alternative when .3dm is not available.
You can do any Rhino operation on objects from imported data, as long as the operation works on the object type. My guess is the model in your link is a mesh model, so a few commands which work on surfaces will not work on the imported mesh. However in most of those instances there is an equivalent command for mesh objects. For example OffsetSrf and OffsetMesh.
Yes.
That depends entirely on what types of objects the imported model is and how it was created compared to how you would create a similar model.
Yes, I routinely use the Contour and Section commands on imported meshes.
Thank you very much Wim for your suggestion, and the fact that your opinions concur with Davids and Marks views does encourage me to proceed along this approach
Import