Stl Import Then Sorting It Out

[jonnyboy]

N00b here...feeling very frustrated!

quick background...I am a student studying motorsport, have got 3d laser scanned data of cylinder head ports in stl format.

http://uni.jcrdevelopments.com/group\_proje...port/ports1.jpg

I can open the stl, but then I don't know what to do with it.

I want to basically be able to use it as a template to draw over to make a simple, yet quite closely accurate model of this.

Ideally i would like to import it into solid edge but i cannot get it to export into an iges file that i can open in SE.

Really dont know where to start...any any any help would be much appreciated.

Cheers,

Jon

[dmercel]

Hi Jon,

This is Dave from the company that scanned the part for you. I was just checking the boards and found this post. Hopefully I can offer some assistance.

I'm not really a massive MAX user, but a collegue who you didn't meet on Friday is pretty efficient with it.

Here goes:

1) Import your model into Max as mesh, which .stl already is, turning off welding and all other import features. This will import the mesh cleanly, without filling up too much memory.

2) Create yourself a NURB plane using the point surface command. This creates a surface that conforms to the vertices that describe it and is forced to travel through them. I would recommend using fairly low densities of vertices on maybe 3x3 to start with otherwise you'll be doing this forever..!!

3) By turning on vertex snapping and sub-selecting the 'point' options under the modifier list for the NURB surface you can 'SNAP' the vertices on to the mesh.

With a bit of practice you'll be able to build up a patch work or as the pros like to call it 'network' of NURB patches that describe your object. These can then be exported to IGES format and read into Solid Edge. Try and join the surfaces before export as well to maintain the integrity of the model.

From my point of view this is easier done in Rhino, but you can get more or less the same result with MAX, it just takes a bit longer.

Good Luck mate.

Dave

[joojaa]

3ds max is definetly not the best tool for the patching thing by the way!

[jonnyboy]

Dave! Good god what a spooky coincidence! I was almost about to contact you directly about this!

I would rather use Rhino too TBH. For two reasons, 1) as you say it seems like an easier package to use and 2) for some reason, Max will open it but has difficulty displaying it (whereas as Rhino has no issues).

I do not have the "plus" or "bonus" menu, that you do on your Rhino app...thats the only bit I remember you showing me which looked like the way to go.

Is it possible to snap to points on the imported stl to use as a kind of template? By this I mean simply by using the circle by 3 points command, for example, then snapping to three points on the mesh where i would like the circle to be.

Basically just attaching simple shapes to the mesh, then being able to turn the mesh off being left with a series of simple shapes, which could then be connected together.

Cheers for your help,

Jon

[dmercel]

Hey Bud,

Yes totally as you suggested you can pick points on the mesh and snap to them to build simple objects and then turn off the mesh to work them up into surfaces.

To do this you need to turn on the POINT snap in the object snap menu. This will allow you to snap directly to the vertices that are at the edges of each triangular face of the mesh.

The snaps can be a bit tricky when you start and it took me a while to actually fiqure out all the projection options, but you soon get your head around it. Just have a play about on a simple object first to understand what they are doing.

The BONUS tools menu can be downloaded from the Rhino site at
http://www.rhino3d.com
then it just installs as an extra menu with no fuss.

I hope it all goes well, and feel free to contact me if you get stuck and I'll do my best to help.

P.S the reason MAX won't display the mesh correctly is because you need to turn on Force 2-sided in the viewport settings, and then in the render settings too. Otherwise it doesn't show the back faces of the mesh objects.

[jonnyboy]

Cheers for that,

Will try again later, but I have to say I am sure I have already tried using object snap (if you mean the one at the bottom of the screen) and it didn't seem to work...but I may be wrong.

Will give it a go.

Thanks again!

Jon

[jonnyboy]

Hmm well it wont do it....it seems to only want to snap to the basic datum grid, like the 0,0,0 plane. It will not snap, even with object-snap set to point, onto the mesh.

Which is odd as I remember doing this at your place. What am I doing differently?

[dmercel]

You need to turn off the PROJECT option at the bottom of the screen since this projects the snap position to the active grid plane. Therefore once you turn it off it will snap to the point where it should and it will stop projecting it.

Like I said it takes a little while to get your head round the snaps, but eventually it does make sense, just be careful what is turned on and off.

[jonnyboy]

I did try switching the project command off but it didn't make a difference. Always wants to snap to the base X-Y construction plane for some reason.

Its almost as if it is ignoring the model...like it is locked or something, but if I tilt the view so I am looking "up" at the underside of the model, so the construction plane is out of "line of sight" then the cursor just comes up with the "no entry" symbol, meaning there is nothing you can snap onto here.

Very perculiar. I shall press on but I am now just randomly pressing buttons lol.

Cheers

[dmercel]

Ok Ok

This sounds like you also have the SNAP button pressed at the bottom of the screen. To prove it can be done, and to show you the Snap configuration to make it work check out the link below.

Rhino Snapshot

Hope this helps.

[jonnyboy]

Well I don't know what going wrong. I am sure I have it set up just like yours. But it will just not snap to the model...cplane only.

Are you simply just importing the .stl and then going straight to work on it?

[dmercel]

Yeah, just import the .stl into the default layer for example and then you can get cracking with it.

One thing to check is your settings. Go to the kinda cog looking icon and thats all your preferences. The snap settings may be tool large or something. You may be importing it at the wrong scale as well. Make sure your units are millimeters.

If you still have problems send over the .3dm file, and I'll set it up for you and send it back.

Alternatively, if you have v3 of Rhino I can send you the one I have here.

Just let me know. That way all the settings will be maintained.

[jonnyboy]

Ok Dave I think I better send you my file, as this is doing my head in. As far as I can see I have everything set up as you suggested. No doubt it will be something small and silly.

I do have Rhino V3, but rather than you just send me a workign file, I would like to know where mine is going wrong.

PM your email addy to use and I'll send the file over.

Thanks for all your effort Dave, I really appreciate it.

Jon.

[jonnyboy]

PM'd Dave.