Implementation of chord primitives


Implementation of chord primitives
#1
16-sided chords come in two types; 1-8, 3-16, 1-4, 5-16, 3-8, 7-16, and 2-4 are made of mostly quads while 5-8, 3-4, 13-16, and 7-8 are made of only triangles. I get that the final triangle count is the same no matter how the triangles are organized.

Nevertheless, the triangle-only solution has a lot of narrow triangles and they are concentrated to the same area. Why is that? I would understand it if the chords were created additively (previous chord + one triangle = next chord), but they aren't.

Should we do something about it?
Reply
RE: Implementation of chord primitives
#2
(2025-08-07, 20:14)Peter Blomberg Wrote: 16-sided chords come in two types; 1-8, 3-16, 1-4, 5-16, 3-8, 7-16, and 2-4 are made of mostly quads while 5-8, 3-4, 13-16, and 7-8 are made of only triangles. I get that the final triangle count is the same no matter how the triangles are organized.

Nevertheless, the triangle-only solution has a lot of narrow triangles and they are concentrated to the same area. Why is that? I would understand it if the chords were created additively (previous chord + one triangle = next chord), but they aren't.

Should we do something about it?

But they are created additively. And they should be made like that if we follow the rules for a primitive.
"Where this fraction is less than an entire circle, the primitive starts at {+x,0} and progresses in a conterclockwise direction when viewed from above {-y}."
If you make a chrd prim in PrimGen2 it is made like that. All triangles starting in the same point (1 0 0)

This however is not important for the mathematical "primitive substitution" that is peformed by some of the SW.
It doesn't care about triangles or quads. Only the radius matters in the mathematical visualisation.

All the chrd-prims with quads have been manually edited after the creation, presumably to avoid thin triangles and instead use larger quads.

Should we change them? I my opinion, no.
All the "longer" chrd prims, 5-8, 3-4, 13-16, and 7-8 should be avoided in a design. It is often better to use "shorter" chrd prims.
Reply
RE: Implementation of chord primitives
#3
(Yesterday, 13:50)Magnus Forsberg Wrote: All the "longer" chrd prims, 5-8, 3-4, 13-16, and 7-8 should be avoided in a design. It is often better to use "shorter" chrd prims.
What problem do you see with them?
Reply
RE: Implementation of chord primitives
#4
(Yesterday, 20:29)Philippe Hurbain Wrote: What problem do you see with them?

Let me rephrase that. I don't see a problem with the chrd prims.
Making new, "longer" edge, cyli, con and ring primitives is to be avoided.
Anything longer that a 1-4 can often be made by adding 90 deg rotated short prims.
Reply
RE: Implementation of chord primitives
#5
If the longer chord prims are to be avoided, could one not update existing parts with the corresponding shorter prims via script and then obsolete those longer prims?

It disturbs me that they are not made of quads
Reply
RE: Implementation of chord primitives
#6
(3 hours ago)Peter Blomberg Wrote: If the longer chord prims are to be avoided, could one not update existing parts with the corresponding shorter prims via script and then obsolete those longer prims?

While I could, that's a lot of effort to fix something that isn't really broken.
Reply
« Next Oldest | Next Newest »



Forum Jump:


Users browsing this thread: 5 Guest(s)