Primitives with mixed subdivisions

[Gerald Lasser]

I am working on the Belville Door, 33216, which has a rounded narrow side which goes along another curve. So naturally it should be a torus.

Now comes the problem: The major radius is 69.5 LDU, the minor radius is 2.5 LDU. The size of the major radius calls for a 48 segment division, but for the other dimension 48 segments are way too much.

So I think a set of primitives would make sense, that have a 48 segment division for the major radius, but a standard 16 segment division for the minor one. This could apply if the major radius is more than 10 times the minor one.

Also, if those primitives, made by the primgen2, have 'only' 4 decimals, the scaling to a radius of 70 leads to gaps, extending this to 5 decimals is a benefit for those applications.

Currently I made a subfile for this special torus-"primitive"

What's your opinion?

[Orion Pobursky]

I am working on the Belville Door, 33216, which has a rounded narrow side which goes along another curve. So naturally it should be a torus.

Now comes the problem: The major radius is 69.5 LDU, the minor radius is 2.5 LDU. The size of the major radius calls for a 48 segment division, but for the other dimension 48 segments are way too much.

So I think a set of primitives would make sense, that have a 48 segment division for the major radius, but a standard 16 segment division for the minor one. This could apply if the major radius is more than 10 times the minor one.

Also, if those primitives, made by the primgen2, have 'only' 4 decimals, the scaling to a radius of 70 leads to gaps, extending this to 5 decimals is a benefit for those applications.

Currently I made a subfile for this special torus-"primitive"

What's your opinion?

I’d say just use 48. Polygon count isn’t much of a problem for a part that isn’t used 100’s of time in a model.

[Magnus Forsberg]

Do you know of the mixed modus primitives?

https://forums.ldraw.org/thread-22187-po...l#pid25498

http://ldtorgen.appspot.com/

It will generate good code, but the header needs some corrections.

[Gerald Lasser]

Do you know of the mixed modus primitives?

https://forums.ldraw.org/thread-22187-po...l#pid25498

http://ldtorgen.appspot.com/

It will generate good code, but the header needs some corrections.

Thanks for pointing this thread out! That's just the thing I need! (before tweaking more with my own VBA code  )

[Gerald Lasser]

I’d say just use 48. Polygon count isn’t much of a problem for a part that isn’t used 100’s of time in a model.

That's true! I would then need to make the cyl also 48 to avoid transition issues. 
I will play a bit with the mixed mode generator as well!