Hi All,

I thought sweep would be the right tool to quickly create a bracelet, so I created a profile, setup a rail , sweep but the created solid does not match the sweep.


Here is the profile





And here is the result.



Am I using the wrong tool?

Cheers, Steve

Hmmm, Since I'm working in mm, the gap between surface and the profile is .02mm at largest point, so I guessing to the naked eye it will look smooth.?

Hi Steve, so the result you see there is actually fine.

The little gap that you're worried about is just a display artifact, your actual solid and surface does not have any gap at that point.

In order for a surface or a solid to be displayed on the screen, it needs to be broken down into a bunch of flat triangles, because your video card hardware does not know how to directly render full surfaces, the video card only knows how to process triangles.

So anyway, surfaces are broken down into triangles in order to be displayed on the screen, and if a somewhat lesser number of triangles was used in a certain area, that can lead to some display artifacts like you're seeing there.

That's just something to ignore - it does not mean that your actual surface is like that, and if you export to a mesh format you can crank the polygon export up to a higher polygon density to generate more polygons in that spot if you want.

You may see those kinds of little display artifacts from time to time, and if it looks really messed up like things leaking out past their normal boundaries then that can be a cause for concern about the structure of your model, but just a slight amount of polygonal profile like that is not something to worry about, it's just that you are seeing some of the flatness of the triangle display mesh.

It's also important for MoI to generate the display mesh very quickly so that you don't have to wait around a long time for it to be regenerated every time you edit the model, so that's why it doesn't try to do enough work to totally avoid all those kinds of display artifacts - that would have a bad side effect of slowing down the display quite a lot.

So it's kind of a side effect of having a quick display that can lead to those kinds of small display artifacts. That's why it's just a normal thing and not a cause for concern on its own.

- Michael

Stevecim,

Go to your Options>View> and lower the "Mesh Angle" number. The smaller the angle, the more polygons have to be written to the vid card.
But if you are patient and can wait until MoI re-draws to the card, then you can get a smooth looking surface that is great for saving screen captures of.
Before going back to manipulating the model, just change the number back to something higher.

For your convenience, put this script in your shortcut keys list in the Options:

script: /* Toggle mesh angle */ var newang, ang = moi.view.meshAngle; if ( ang == 5 ) newang = 15; else if ( ang == 15 ) newang = 25; else newang = 5; moi.view.meshAngle = newang; var sidepane = moi.ui.getUIPanel('moi://ui/SidePane.htm').document; if ( !sidepane.getElementById('meshangval') ) { sidepane.body.insertAdjacentHTML( 'beforeEnd', '<div id="meshangval" style="position:absolute; right:5px; bottom:5px;"></div>' ); } sidepane.getElementById('meshangval').innerText = newang;

Then you can toggle through a few mesh angle choices on the fly, and the number will be displayed at the bottom of your command panel.

Hi Steve,

> Hmmm, Since I'm working in mm, the gap between surface
> and the profile is .02mm at largest point, so I guessing to
> the naked eye it will look smooth.?

It probably would be hard to notice it - but the gap there is just a gap between the on-screen "realtime" display mesh and the edge curve, it's not a gap in the actual surface itself.

When you go to export to a mesh format like STL or whatever, you will be able to adjust the export options to generate a denser mesh at that time if you want, and if you made it denser than that display mesh you would see that area actually get filled in with polygons to make it smoother than that.

You end up seeing a gap in this case in the on-screen display because curves get displayed by the display engine to a high degree of accuracy - they're continuously refined until the on-screen display is within a screen pixel of the true curve geometry.

But unfortunately it would take too long to do that equivalent "1 pixel display accuracy" type thing with surfaces, so surfaces get a somewhat rougher display mesh calculated for them just one time and then that display mesh is used for all display of it after that, it's not recalculated when you zoom in closely unlike the curve display.

So anyway, that's why you may see some disagreement between the shaded surface display and the display of an edge curve - the edge curve display is much closer to the actual model geometry while the surface display is kind of rougher in order to keep things fast.

That rougher surface display does not mean that your actual surface itself is rough though, it's just that current on-screen display that looks like that, when you go to export you can generate a denser mesh at that time if you want to.

- Michael

Hi Steve, also to answer your actual question - Sweep is probably the right tool for what you're trying to do.

It's a little hard for me to be 100% sure because I only see just one view of your model there and it's a little bit hard for me to understand the full shape that you're trying to create. When you post a question, it can really help if you also attach the 3DM model file with your actual objects in it so I can actually load the model file and look at it from various angles and zoom in on it, etc... all of which can't be done with just a screenshot.

- Michael

> also to answer your actual question...

You can also use the Revolve command, choosing the center axis of the bracelet and choosing you profile. Same result.

There are about three other ways I can think of to get the same result, MoI is good that way.

Big Thank you to everyone that responded.

I managed to get what I wanted using both sweep and revole and learnt a bit more about MoI :)

In my book, any day you learn something is a good day :)