New Prim Type..partial circle

I don't know if this would be computationally difficult to calculate or render, but here goes:

I think it might be useful to have a prim which could represent a portion of a circle. In addition to the standard torture settings, it would need the ability to set the radius of the total circle containing the outer edge of the prim on its circumference. (Or maybe direct-set the circumference, or diameter...whatever.)

if the diameter/circumference/whatever was greater than could be handled by the current length of the prim, the inner edge would be automatically re-shaped to the appropriate inner arc. The maximum width of the prim in any one direction could still be The Old Community Standard.

Kind of opens an interesting question as to how to handle the prim if X != Y...a calculated ellipsoid seems the obvious answer.

-yoshi

If I am understanding, couldn't you just cut an existing prim?

Not exactly what I'm after, Goshua...let's say I had in mind to build a semi-circular deck that would, if completed as a circle, be 30 meters in diameter.

What I'd like to be able to do is rez a 5-meter long prim that would shape the outer edge so that, if correctly aligned and rotated with identical prims at 10 meters from the origin of the circle, would form a seamless outer rim 15 meters out with proper curvature. The inside edge of the prim (pointed toward the deck's center) would be auto-shaped to fit against the rim of a circle which was 10 meters in diameter.

In other words, I want a kit piece which can be a part of an arbitrarily large and "perfectly" round cylinder.

- yoshi

ahhhhh a good idea, Yoshi, I could use that
Along with the being able to type in positions when in Local View and be able to have the typed in Positions to coincide with Local, not global

BCP = Box's Cylinder's Prism's

The settings for it should be

integer holeshape, vector cut, float hollow, vector twist, vector topsize, vector topshear, vector insideradius, float totalsize, integer texturestretch

Twist would effective twist the section around the center of the circle. To make a round shape of <28,22,2> with a <8,4,2> void in the center you would use twist and the same size to make all the parts by making the twist begin and end the same. The x & y size's would be the same for this shape.

The twist delta would effect the overall max size of the shape. Twist begin would move to accomidate twist end as to not violate the total size restriction.

Top shear and size should act like the way they do in BCP.

insideradius would be the proportional distance (in x & y) from the center of the big shape to the edge of the shape.

the object rotation would allow you to rotate each section into place, twist would have no effect on the objects rotation in this way (unlike how it works with BCP).

hollow and cut would work like it does on BCP.

Default hollow shape will mimic the shape of the section.

Advanced Cut should carry over and should be applied like it is with BCP.

The range for inside radious should be 0->100

texturestretch would effect how textures are teated. If they are treated like they are on the tops of tubes or as they are on the tops of cylinders. (TRUE=TUBE, FALSE=CYLINDER)

insideradius.z=1
((insideradius*size)+size)*totalsize = size of finished shape. (dot product for vector-vector multiplication)

Inside Radius
|-----------|
	      _ .  ~  ' |
.	    |           |
	      `   -   _ |

so for your <28,22,2> object you with the center cut-out cylinder of <8,4,2>
would require...

x=              10
y=              9
z=              2
holeshape=      DEFAULT
cut=            <0,1,0>
hollow=         0.0
twist=          <0,0,0>
topsize=        <1,1,0>
topshear=       <0,0,0>
insideradius=   <0.4,(4.0/9.0),0>
totalsize=       2.0
texturestretch= FALSE

totalsize is used to regulate the number of sections used in the shape.

have i missed anything?

PS. The more i think about this the more complicated it's getting. I currently don't really need this.

what about new shape=teapot?

j/k!

It's probably already in there somewhere, hidden. After all, the teapot is the key primitive in OpenGL.

zzzzactly

Actually, I'd like to see Extrude, Revolve, slice, Boolean operations, skin meshes, and cookie cutter operations, but I know that's just wishful thinking.... for NOW that is! muahahaaaa

Aah from the mind of a CAD guru LOL

Arti

Yes.. I'm all for boolean operations, such as intersect, add, remove, etc.

if you want a 30 meter semicircular deck, why don't we just have 30 meter prims? if the number of prims is limited for each sim doesn't it make sense to have bigger prims instead of using alot of small ones?

and while we're at it, smaller prims! i feel sorry for all the people who want to make a 9 mm gun when the smallest a prim can get is 10 mm.

They should just let us resize cut prims proportionally to the cut. So that a 50% cut prim could be 10 meters in length instead of 5.

and I'll add a script to its contents called "Tempest".



- Ace

ooh, now a mesh "primitive" with equivalent prim params would suit me just fine!

what eggy said only it'd have to lock to that cut until we lowered the size. otherwise we could halve a prim, stretch it to ten meters, then uncut it to a twenty meter prim. well now that would just be perfectly awful.

is a 20 meter circle big enough?

llSetPrimitiveParams([9, 5, 63, <0,1,0>, 0.0, <.25,0,0>, <0,0,0>, <0,0,0>, <0,1,0>, <0,0,0>, 1.0, 0.0, 0.0, 1, 1, <0,1,0>, 0.0, 0.0, <1,0,0>, <0,0,0>, 1, 5, <0,1,0>, 0.0, 0.25, 0.0, 7, <10,10,10>]);

course it has no x demention...

Instead of partial Circle, how about Arc?
X 30.00 meters
y 30.00 meters
z 0.25 meters

then advanced controls:
Set Arc Radius 0-90 degrees
Set Arc Width X (meters)
Set Arc Width Y (meters)
This might help with the 10 meter object limits in SL and keep the object within the 10 meter size constraints.

I'd like to be able to make bigger prims, but I'd settle for being able to make a 10x10 arc segment of a bigger circle. Ten by ten sounds big until you want to make a round room, and you can't walk around in it without having your camera stuck outside (and Mouselook is useless, but I've already contributed to one of those threads today). Also, I'm interested in making some larger round "temple like" buildings (see the link in my sig to see why), and they just don't look right at smaller sizes or with flat walls. I've seen the excellent curved wall builder scripts, but they use up a bunch of prims, and I'm always on a prim diet.

What *is* the problem with bigger prims, anyway? I don't mean this rhetorically, I honestly don't know the answer. The only thing that comes to mind is that one can block one's neighbor's view more cheaply with bigger prims, but if you really want to be a pain about this, you can just do it with more prims. It can't be server load. That should be about the same regardless of prim size.

Anybody want to clue me in?

Neko