Help with solids and surfaces

[razor]

Question #1:

I have a little problem. First off, I'm new to this. So be gentle . Our shop has recently purchased MasterCam and I've been playing with solids. I have no problem when I create the solid, running tools over it. But I've recently found a site to get 3D wireframes from.

3D cafe

But I can't seem to do any surfacing on them. They seem to have been created in AutoCad and DXF'ed out.

Is there a way to use these wireframes to run tools over them and create 3d objects.

Question 2: How do you create surfaces from a dumb solid?

I was just asked to help out the programming department because I used to be a programmer. But the last software I used was Gibbs( before virtual ). Help if you can. Thanks.

[kwolf]

Hi Razor,

1. if you can't do anything with surfaces in Mastercam try using rhino3d v2. A NURBS modeler for creating and editing surfaces.Even it has the capabilities to create organic surfaces.you can get a free 25 save evaluation version at www.rhino3d.com .

2. you can use make surface from solid face option in mastercam.

hope it helps

[ 11-30-2001: Message edited by: kwolf ]

[bryan.davis]

solids/surfaces/wireframes the basics

1 there is no such thing as a dumb solid in mastercam.

You dont need to create surfaces from a solid as by definition a solid is a collection of surfaces conected allong their coedges to form a 'watertight' body. Some packages treat imported solids as 'dumb' but mastercam isnt one of them, all geometry imported into mastercam is immediately native and can be treated in exactly the same manner as solids or surfaces created in mastercam,

2 So what have you got?

What you have to first identify is exactly what sort of file you are looking at and there are several ways of doing this.

Firstly the file type is a big clue, certain file types are only capable of containing wireframe data (DXF, CADL etc), others can only contain surfaces and wireframe (IGES) whilst the likes of X_T, SAT, MC8 and STEP are full blown solids/surfaces and can often contain wireframe (but not always)

Another quick and sure way to identify whether your file is a wirefram file or a solids/surfaces file is to do a 3D render (thats the blue globe icon on the toolbar), just activate that and look for the part in the file to be rendered as a solid non-transparant image, if the part image does not change then youve got wireframe data only, and cant do any surface machining on it untill you recreate the surfaces...actually you can do some basic surface machining using the old swept toolpaths, but thats history...

If however you see a solid looking image then youve got a solids or surfacs file and should be able to do surface machining providing youve got level 2 or 3 mastercam, if youve only got level 1 then this whole topic is academic!

3 that cant be right Ive seen a solid image of the file

Now you've mentioned DXF and 3D cafe so Ive done a little checking for you and the DXF files there DO NOT contain any solids or surfaces data, (they cant because they are dxf files), they are mearly polygonised 3d wireframes that are likely to have been generated from a solid.

Some cad packages can give you a solid looking image from a 3d polygon wireframes (cadkey for example), but MasterCAM cant, and this is not to be confused in anyway with a solid or surfaces.

Some cad packages can also convert wireframe into a true solid (or surfaces), again cadkey can and mastercam cant, but in my experience this is not a reliable process on anything but the most simple and basic shapes.

4 But I want solids or surfaces

well without a solids file of the part, the best way to go about this is to take your wireframe polygon file and recreate the surfaces manually, half the work has been done for you, all you have to do is apply the surface creation tools to the wireframe, howevr, you may like to modify the geometry somewhat as the facet sice is those files is pretty chunky and you are going to end up with a very rough looking modle

 

good luck and hope this has helped clarify your probelm

[d0gFartz]

quote:

---

1 there is no such thing as a dumb solid in mastercam.

You dont need to create surfaces from a solid as by definition a solid is a collection of surfaces conected allong their coedges to form a 'watertight' body. Some packages treat imported solids as 'dumb' but mastercam isnt one of them, all geometry imported into mastercam is immediately native and can be treated in exactly the same manner as solids or surfaces created in mastercam

---

no offense but please explain to me why when i import a solid into mastercam in the manager its just 1 body,mastercam doesnt use feature recognition as far as i know like you can on Solid Edge and i think Solid Works does it also,

mastercam solids imports it as 1 BODY that has no features defined in the solid manager tree

[ 12-01-2001: Message edited by: d0gFartz ]

[gcode]

You can create a suface for a solid (smart or dumb) by clicking

Create/ Surfuce/next menu/ from solid.

That will give you the solids selection menu where you can select the whole solid of indivisdual surfaces.

It helps if you use a different color and layer to create these surfaces. That way its easier

to keep the solid faces and the created surfaces seperate

[bryan.davis]

well OK for those of you who reckon you need a parametrics tree in order to do anything to a solid then there is such a thing as a dumb solid, ie a solid without a parametrics tree.

For the rest of the world who know that the parametrics tree is little more than a gimmick and are perfectly capable of living without one then there is no such thing as a dumb solid, and this is even more true for those who dont use solids in mastercam and just use surfaces.

[razor]

I think I understand. I have to recreate the Solid or surfaces from the wireframe in order to run tools over it. I do thank you for the help.

[cadcam]

Yes Razor,

After all this that is the bottom line.

Good luck.

You need help you know we are all just a click away.

[Guest CNC Apps Guy 1]

Technically speaking a "Dumb Solid" is a Solid Body with no history, so there is(technically)such thing as a Dumb Solid In Mastercam. Once in Mastercam though you can modify the solid body.

Here is Mastercam's Take on what a Solid is. This is from the Help File in Version 8.1.1

quote:

---

Solid modeling refers to the process of creating solids. Unlike wireframe models, which are a collection of curves, and surface models, which are a collection of surfaces, a solid model is a single entity, regardless of its complexity. You work with a solid model as a whole, like molding a piece of clay, rather than building a model from a series of unrelated entities. For example, you can add fillets to a solid, then hollow it out, and even combine it with another solid—it still remains one entity.

Because a solid is a closed, organized model, Mastercam is able to keep track of the inside and outside of the model for you. This characteristic makes solid modeling easy because the system handles the complexities of the model behind the scenes. You never have to determine the surfaces that you want to keep or trim when you perform operations on the solid. The system automatically performs these actions for you, always maintaining each solid as a single entity.

---

Pretty much says it all IMHO

[bryan.davis]

True, but I come from a non parametrics background and my definition of a dumb solid is one where you cant perform any solids operation on and can only be used for reference purposes... I guess us non parametric boyz have a much more inteligent definition of dumb

btw seen a demo of MCAM 9 and with the feature recognition that should be fixed too

[Guest CNC Apps Guy 1]

quote:

---

........btw seen a demo of MCAM 9 and with the feature recognition that should be fixed too

---

..... and a host of other new stuff to boot.

I'll just say to the critics of V9, "You've got it all wrong, there's a TON of powerful new stuff in V9".

I've been using V9 since it was released for Beta Testing(well maybe a few weeks after but you get the idea) and I have not used V8 for ANYTHING since. V9 just too good. Now is the time to start thinking about upgrading guys (and gals - for Kathy, speaking of which, is she buried in some project????) and "priming your bosses and bean counters for the $$$$ for the upgrade.

Don't wait until V9's been out a year and a half or so because by then V10 will (most likely) be in Beta Testing. Get in on it early. BTW I get no ca$h for my endorsement of Mastercam. I'm just a regular guy who uses it every day to program my parts with it just like the rest of you.

Have a nice day.

JM2C

[gstephens]

What you're getting from 3d-cafe are basically STL files (without the face direction definition - which means you can't cut them directly). The wireframe you get from them is going to be almost impossible to re-create as a surface or solid in Mastercam. The best you could do is to create all of the endpoints and use something like revsurf to convert the point cloud into surfaces. VERY time consuming and not always what you want/need.