Re: 3D Modelling of a fish

IBB98 · ‎Feb 26, 2020

Note: Files are saved in Creo Parametric Student Version

Hi, I am attempting to create a 3D model of a fish for 3D printing.

I have a 3D model already (.obj file) however it doesn't seem to want to work. I would like to convert that .obj to a solid so I can edit it with Creo Parametric but I am having difficulties. I am not used to working with .stl or .obj files that make use of facets. (What I would like to do is split it into several parts (allowing for maximum printing area constraints on 3D printer) and increase the thickness of the walls.)

As that doesn't seem to want to work for me I am attempting Plan B. Please see attached a sketch of the fish (i.e. a 2D sketch in .prt format), the .obj file and a .prt file created by importing the .obj file and saving as a .prt. The sketch has been made by roughly tracing the outer boundaries of the .obj file. (It doesn't have to be perfect.)

If someone could advise the best possible way for me to convert the sketch into a 3D model (similar to the part created by the .obj file however with thicker walls) that would be fantastic. i.e. would an Extrude, Sweep, Revolve etc. work best?

Thanks very much for your time,

Ian

MartinHanak · ‎Feb 27, 2020

Hi,

I asked Google ... Creo convert that .obj to a solid

and received following link

https://www.youtube.com/watch?v=ho-t5OgEbJY

Martin Hanák

IBB98 · ‎Mar 02, 2020

Thank you, I will attempt this tonight and get back to you.

IBB98 · ‎Mar 02, 2020

I can get as far as 1:16 in that video following the steps detailed to create a skrinkwrapped model, as seen in Capture1 below, however as soon as I attempt to click okay the geometry disappears and I receive the message 0 triangles produced. This happens regardless of what Quality level I attempt to use. Has anybody any experience with receiving this message? Does anyone know of a solution?

This is now added to the long list of different attempts I have done changing this .obj to a solid .prt, this is why I conceded defeat and attempted to create my own without much luck...

MartinHanak · ‎Mar 02, 2020

@IBB98 wrote:

I can get as far as 1:16 in that video following the steps detailed to create a skrinkwrapped model, as seen in Capture1 below, however as soon as I attempt to click okay the geometry disappears and I receive the message 0 triangles produced. This happens regardless of what Quality level I attempt to use. Has anybody any experience with receiving this message? Does anyone know of a solution?

This is now added to the long list of different attempts I have done changing this .obj to a solid .prt, this is why I conceded defeat and attempted to create my own without much luck...

Hi,

I downloaded your TUNA.OBJ and opened it in Creo
there are 3 separate facet features
I deleted facet feature representing eyes
I deleted facet feature representing mouth
I edited facet feature representing fish (I am not sure if your license enables you to do this action)
- I filled 3 holes (2 eyes + mouth)
- I remove 1 facet in dorsal fin (it contains 1-side edge)
result ... closed volume
I created shrinkwrap part
I opened shrinkwrap part and created tuna_stl.stl
you can download tuna_stl.stl, open it and create shrinkwrap part ... I wish you success

Martin Hanák

IBB98 · ‎Mar 02, 2020

Thank you so much for your help!

IBB98 · ‎Mar 03, 2020

Hi Martin,

Thanks so much for your help. Using your .STL file (scaled to size) I have successfully created a Shrinkwrap part using Level 10 Accuracy. Please find this attached below. However, it isn't as accurate as I would have liked. In order to 3D print my model on a printer bed sized 200mm x 200 mm, I have split it into three separate parts: a front (nose) section, mid section and tail section. Please find .STL files of all of these parts attached.

I was wondering if creating a shrinkwrapped part of each of the three parts separately would be more accurate than the overall shrinkwrap as there are less facets? I have attempted to do this but have run into the same problem as before, obviously because it can only work on a closed solid part, not one with holes. Can the Creo Student software fill these holes in order to shrinkwrap these three parts? Or is there another software I can use to edit the .STL and fill the holes as you did previously?

Thanks again so much for your help,

Ian

MartinHanak · ‎Mar 04, 2020

Thanks so much for your help. Using your .STL file (scaled to size) I have successfully created a Shrinkwrap part using Level 10 Accuracy. Please find this attached below. However, it isn't as accurate as I would have liked. In order to 3D print my model on a printer bed sized 200mm x 200 mm, I have split it into three separate parts: a front (nose) section, mid section and tail section. Please find .STL files of all of these parts attached.

now you know that Shrinkwrap geometry is different from source STL geometry
how did you split STL ?
why do you need solid geometry ?

I was wondering if creating a shrinkwrapped part of each of the three parts separately would be more accurate than the overall shrinkwrap as there are less facets? I have attempted to do this but have run into the same problem as before, obviously because it can only work on a closed solid part, not one with holes. Can the Creo Student software fill these holes in order to shrinkwrap these three parts? Or is there another software I can use to edit the .STL and fill the holes as you did previously?

if you need to fill holes try editing definition of Facet feature ... I am not sure whether Educational license enables you do do this
I do not have enough time to solve your problems ... this is up to you 🙂

Martin Hanák