Working with meshes tutorials and any command to place surfaces and curves?

Rhino Rhino for Windows
1

Hi
V5

I could do with a beginners guide on importing meshes in Rhino, made from within photogrammetry programs such as Agisoft Photoscan, orienting them, even a command that might be used to place curves on the mesh and then surfaces between such, best fitting a mesh , to use as a start point to then tweak. The goal being to end up with an accurate curves and surfaces model representing the engineering item I have photographed and turned into mesh using such as Agisoft.

I have a lot of projects that will start with capturing an object in 3D, I cant afford a scanner (who can ?) so I am using Agisoft Photoscan, generate a mesh from the object, then need to create a rhino model by sectioning the mesh, drawing curves to match it, create surfaces from curves, in other words turn the mesh into a hand crafted rhino model. Even folk with scanners need to then create and model a surfaces model from the scan. How is it done ? I am capturing engineered shapes including organic shaped forms such as exhaust manifolds.

any videos on meshes and rhino as its totally new territory for me and I need to read up or view videos, (far preferred) on it.

Cheers

Steve

1 Like
2

Hi Steve,

At start figure out what file format your software exports. My bet is on Obj. :wink: I don’t know anything about working with meshes so that is kinda all I can help with. I am also looking for some advanced tutorials for that. Makeing use of vertex-vertex relations.

3

Hi, it has obj stl 3ds dxf pdf
I presume obj is the way to get the mesh into Rhino.

so you like me are after beginners help and tutorials on this.

Steve

1 Like
4

I export textured meshes in .obj format from Metashape and import them into Rhino. My recollection is for the textures to work properly the file names should not have spaces but I don’t recall if that was needed on the Metashape or Rhino end.

I rotate the axis system in Metashape before exporting (typically after creating the initial point cloud) so that the the object (usually a boat for me) is roughly aligned with the axis.

After the mesh is imported into Rhino I align it as desired. The process and commands is the same as I use with any other object. I’ll frequently create reference points or lines to use for alignment. Sometimes I need to create a best fit reference plane on a nominally planar portion of a mesh and then use that reference plane in the alignment process. Usually several iterations of alignment are needed, alternating between views and using Rotate or Move to tweak the mesh into its final position.

5

Hi David,

That allays my fears that Rhino could create a mesh but was not designed to import one, then be able to align it. as I read and refer to at foot of this post.

Did you find any tutorials on bringing in and working on meshes ?
I believe in reading up or viewing tutorials and getting a certain amount of knowledge under my belt before tackling something new.
with no responses from the Rhino team I was and still am concerned there is nothing.

I need to place sections through my meshes, then redraw the shapes using rhino tools etc, and surface it.

Any auto tools that will attempt to surface a mesh would be useful.

You and I are using Agisoft, I am struggling even to get the prog to make a mesh for situations where I have moved the object to photo its underside etc, as folk do, I have combined your mask from model method with steps Alexey sent and saw the masks created per photo, :grinning: then merging chunks and removing masks as per your post 1.4.5 (photoscan) produced a mess. prior to that I didnt remove masks, same mess.

I could desperately do with some guidance from you ( I did PM you) but this rhino forum is not the place for such.
You photographing boats with a moving background walking around them and I mechanical objects laid on concrete or gridded table also walking around them should be able to get decent end results. I am just missing a vital step somewhere. I turn my objects to photo sides then turn again for underside, you don’t do that !

we have a great forum here with Rhino, Agisoft one can wait forever on some posts, so moving fwd is in stops and starts :roll_eyes:

The thing is, people are using laser scanners on engineering objects, they produce meshes, there has to be a way of working with meshes to turn that mesh into a suitable file using Rhino curves and surfaces. There must be loads of tutorials . or is it as someone said that Rhino is not truly the prog for such ?

I did see someone posting the fact that Rhino was not suitable for such workflow, he couldnt even get an ability to select the mesh so as to work on it, orient it etc. I had assumed Rhino could.

Steve

6

Rhino is perfectly usable for this. Search for Reverse Engineering. It is not a command but a job description. There are various plugins for mechanical and organic meshes but it also works without. Importing mesh, orient, cleanup, creating sections or contours, projecting curves, rebuilding polylines, creating curve networks, surfacing etc. This is the usual workflow.

_
c.

7

Thanks Clement,
great news then, I just have to try and find the tutorials on all this. maybe there is an entire section called rhino and meshes and reverse engineering, all those bods with scanners (wish I could afford one) need such, David and I instead take loads of photos.

that term reverse engineering is the catalyst ! I see toturials, even plugins for rhino should I find the default tools inadequate.

Has v6 been given more ability than v5 for this working with meshes ?

Steve

8

Apart from the faster display speed i would say everything works as before.

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c.