Full Version: Best way to create dome?

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Hi Matadem, one of your curves is a little short, this could be what is causing problems doing a boolean with something created from it:





Also it kind of looks like there may be some duplicated faces in your ellipse solid.

For making a dome the rail revolve command (Construct > Revolve >Rail revolve) can be good for that:
https://moi3d.com/4.0/docs/moi_command_reference7.htm#railrevolve

You set up a side profile curve like this:



Then select the profile, run rail revolve, then at the "Select rail curve" prompt select the ellipse, then pick 2 points for the revolve axis.

I'll see about setting up your file like that shortly.

- Michael

Image Attachments:
matadem_dome1..jpg  matadem_dome2..jpg 

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Hi Matadem, here attached is the set up for your shape using rail revolve.

First select the profile curve:



Run Construct > Revolve > Rail revolve.

The prompt will say "Select rail curve". Select the top ellipse edge:



The next prompts will say "Pick revolve axis start point" and then "Pick revolve axis end point". Pick these 2 points on the center axis line:



A solid dome with the bottom capped will be created and you can boolean union this onto the base extrusion.

- Michael

Attachments:
dome2.3dm

Image Attachments:
matadem_dome3..jpg  matadem_dome4..jpg  matadem_dome5..jpg 

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Thank you.

Question what is the way to check were to curves do not connect?
Without asking I would have wasted allot of time...since I have never needed to use that rail revolve until today.

Thanks!

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Hi Matadem,

re:
> Question what is the way to check were to curves do not connect?

Just by zooming in a bit to get a closer look at the ends.

The "Area" zoom is good for targeting a specific point, the view will be centered on the first point that is picked.

Like this:



- Michael

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Ok I managed to do this...but ran into another problem.

When I export this as an stl file (set to more polygons) and import into Vectric vcarve the surface is not smooth.


What can cause this?

Tnx!

Image Attachments:
jaggedstl.JPG 

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Hi Matadem, you can get that on shapes that are large but only shallowly curved.

For those kind of shapes you'll need to adjust one of the additional meshing parameters so it will subdivide it more.

Press the little arrow in the lower left corner:


That will show some additional meshing controls.

Then put in a distance value in the "Divide larger than" option. That will divide any polygon larger than that distance.

You don't want to put too small of a value in there since you don't want to generate 100 billion triangles. Start with something around 1/20 of the distance across your model and reduce it in steps until you see the triangles are small so capture more detail but not microscopic.

For your model here a distance of 1 unit would be good:



- Michael

Image Attachments:
matadem_dome6..jpg  matadem_dome7..jpg 

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Works great.

Tnx!

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