Hi Jonah, the only problem with that is that with n-gon generation, edge tessellation does not really play any role in polygon count.

The tessellation of edges controls how many points an n-gon is made up of, but the actual count of polygons is driven only by subdividing the surface.

This is basically the reason why an n-gon mesh has a lower polygon count than a triangulated one - one single n-gon can have an arbitrarily complex border on it without forcing it to be broken up into more polygons. With triangles a more complex or dense edge border does mean more polygons...

Maybe I'm not following you correctly though, maybe an illustration... ?

- Michael

I mean if you want to prioritize the brep edges to have a significantly higher density than interior surface areas, is there any way to do this? I see right now edges do have priority. But it's not very extremely biased. Sometimes it might be useful to amplify this... In this image, the shape is relatively flat, except near the edges. Near the edge, the surface curvature changes greatly and the boundary has a very curvy shape. For rendering, you could get away with some very large n-gons in the interior portions. But close to the edges, it must be more dense to hold the shape... It's nothing of great urgency, i was just curious if this was possible. "Freezing" sounded like a good way to prioritze a setting with just one slider. Or maybe there could be a "bias" slider?

Or maybe it's just not possible?

thanks,
jonah

Hi Jonah, I guess I got confused by terminology.

Part of the meshing process involves converting edge curves into a polyline. When you were talking about brep edges I thought you were talking about this part of the meshing process.

Fundamentally to get more polygons involves subdividing the surface more. To have more polygons near an edge curve would mean trying to detect the parts of the surface that were nearby an edge, and using that as part of the surface subdivision process. That's possible, but might be kind of difficult to make well behaved with arbitrary trim curves that were squiggling all around in uv space...

Part of the current mechanism is an angular threshold - this should generally cause more polygons to get created in more tightly curved areas. It sounds like you want some kind of magnification of this effect?

- Michael

i guess it can be thought of as amplifying the subdivisions around the more extreme curvature. Is there any way to link a minimum edge length with a specified angle tolerance? Such as: if angle is greater than "?" degrees and edge length is less than "?" then attempt to subdivide further until condition is met? Or is this what's already going on in the mesher?

jonah

I believe what Jonah is asking for Michael is a way to boost the meshing accuracy (resolution) around curvy parts while holding the interiors at a lower density during export.

Similar to the display mesh innaccuracies around curvy parts requiring the display mesh angle to be lowered to preserve the display fidelity.

-Will

Hi Jona, currently it's kind of the reverse of that - you can set an edge length by "Divide larger than", which will then subdivide first by angle, and once angle is satisified it will look at the edge length and if it is larger than that value it will subdivide it.

So this increases subdivision for larger edges, it looks like you're talking here about increasing subdivisions for small edges into even smaller bits?

- Michael

"...it looks like you're talking here about increasing subdivisions for small edges into even smaller bits?..."

Exactly! :) Maybe i've been explaining it backwards. I guess what I'm ultimately looking for is a sub-setting of "Divide Larger than", where you can create a window to exclude those edges which exceed a certain length and also exclude those edges which are less than a certain length. so if i first meshed an object with a maximum edge length of "X", then it would give me an option to fuirther reduce any edge which is shorter than "X" until it reaches a second minimum length value. Although that sounds really complicated when explained like this. From a user's point of view, i would be very happy to just have a bias adjustment in the mesh dialog, and have Moi work it's magic behind the scenes... but if it's not possible then i understand...

Thanks,
jonah

I don't really know how I would implement a bias adjustment... But maybe something will come up after letting it percolate for a while.

In general the angular threshold is supposed to be doing the general overall goal that you're asking for - less polygons in flatter areas, and more polygons in more tightly curved areas. Can you please post your example object so I can see why it is not working well in that situation?

- Michael

Hi Michael. sorry for the delay. I have nothing critical at the moment. But when i have a good example, i will send to you. For now, it's more of a generalized wish...

jonah