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Primitives Reference

2023-11-27T14:52:44Z

Swampkryakwa: /* Test */

'''LDraw Primitives Reference'''

This page is a source of reference for the LDraw primitives in the \LDraw\p directory. Primitives are defined as highly re-usable components of LEGO parts modelled for LDraw.
They serve several purposes :

* To speed up parts authoring by providing a library of components which can be incorporated into several parts
* To allow rendering software to make substitutions of curved components

Within this reference material the available primitives are categorised into:

__TOC__
__FORCETOC__

Each section contains an overview of the characteristics common to all primitives within that category. Primitives are grouped into classes within each category - one class of primitive serving a similar purpose at different sizes or resolutions. For each class of primitive, a brief description of the purpose of the primitive is provided, with notes on its co-ordinate origin, default size and rules for scaling. A list of the available primitives is shown.

An understanding of the orientation of the co-ordinate axes is essential for authoring a part for LDraw. For reference within this page the axes and their direction is shown in this diagram.

[[File:Xyzaxes.png|thumb|alt=Axes]]

==Rectilinear primitives==

These rectilinear elements may be scaled in the {x}, {y} and {z} dimensions to make elements of any size. For example

''1 16    0 0 0    40 0 0    0 1 0    0 0 20    rect.dat''

would generate a 80LDu x 40LDu rectangle in the {x,z} plane.

Although the default orientation of the rect.dat primitive is in the {x,z} plane the LDraw language allows for this to be transformed

''1 16    0 0 0    0 1 0    40 0 0    0 0 20    rect.dat''

would generate a 80LDu x 40LDu rectangle in the {y,z} plane.

''1 16    0 0 0    40 0 0    0 0 20    0 1 0    rect.dat''

would generate a 80LDu x 40LDu rectangle in the {x,y} plane.

{| class="wikitable"
|+
=== Two dimensional ===
|-
| '''rect.dat''' || '''Rectangle with all edges'''
|-
| [[File:rect.png|200px|thumb|alt=Rect]]
|| This primitive represents a rectangle in the {x,z} plane and the four edges that bound it. Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions. To avoid matrix arithmetic problems in some renderers, the third dimension ({y} in the default orientation) must be given a non-zero scaling factor.

1 16    0 0 0    5 0 0    0 1 0    0 0 20    rect.dat
|-

| '''rect3.dat''' || '''Rectangle with 3 edges'''
|-
| [[File:rect3.png|200px|thumb|alt=Rect3]]
|| This primitive represents a rectangle in the {x,z} plane but excludes one edge {-z}. Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|-

| '''rect2p.dat''' || '''Rectangle with 2 parallel edges'''
|-
| [[File:rect2p.png|200px|thumb|alt=Rect2p]]
|| This primitive represents a rectangle in the {x,z} plane but excludes two parallel edges ({+x} and {-x}). Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|-

| '''rect2a.dat''' || '''Rectangle with 2 adjacent edges'''
|-
| [[File:rect2a.png|200px|thumb|alt=Rect2a]]
|| This primitive represents a rectangle in the {x,z} plane but excludes two adjacent edges ({-x} and {-z}). Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|-

| '''rect1.dat''' || '''Rectangle with 1 edge'''
|-
| [[File:rect1.png|200px|thumb|alt=Rect1]]
|| This primitive represents a rectangle in the {x,z} plane but include only the one {+x} edge. Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|-

| '''recte3.dat''' || '''Empty rectangle with three edges'''
|-
| [[File:recte3.png|200px|thumb|alt=Recte3]]
|| This primitive represents three edges of a rectangle in the {x,z} plane. Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|-

| '''recte4.dat''' || '''Empty rectangle with all edges'''
|-
| [[File:recte4.png|200px|thumb|alt=Recte4]]
|| This primitive represents the four edges of a rectangle in the {x,z} plane. Its origin is at its centre and by default has a size of 2LDu in each of the {x} and {z} dimensions.
|}

{| class="wikitable"
|+
=== Three dimensional ===
|-
| '''box.dat''' || '''Cuboid with all faces and edges'''
|-
| [[File:box.png|200px|thumb|alt=Box]]
|| This primitive is used to define a cuboid. Its origin is the centre of the cuboid and by default has a size of 2LDu in each of the three dimensions.
|-

|-
| '''box5.dat''' || '''Cuboid with 5 faces and all edges'''
|-
| [[File:box5.png|200px|thumb|alt=Box5]]
|| This primitive represents a cuboid missing the top {-y} face. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box5-1.dat''' || '''Cuboid with 5 faces without 1 edge'''
|-
| [[File:box5-1.png|200px|thumb|alt=Box5-1]]
|| This primitive represents a cuboid missing the top {-y} face and one edge {-z} of that. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box5-2p.dat''' || '''Cuboid with 5 faces without 2 parallel edges'''
|-
| [[File:box5-2p.png|200px|thumb|alt=Box5-2p]]
|| This primitive represents a cuboid missing the top {-y} face and two of the four edges surrounding that. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box5-4a.dat''' || '''Cuboid with 5 faces without top edges'''
|-
| [[File:box5-4a.png|200px|thumb|alt=Box5-4a]]
|| This primitive represents a cuboid missing the top {-y} face and the four edges surrounding that. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box5-12.dat''' || '''Cuboid with 5 faces missing all edges'''
|-
| [[File:box5-12.png|200px|thumb|alt=Box5-12]]
|| This primitive represents a cuboid missing the top {-y} face and all edges. Its primary use is for sticker parts. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4.dat''' || '''Cuboid with 4 parallel faces and all edges'''
|-
| [[File:box4.png|200px|thumb|alt=Box4]]
|| This primitive represents a cuboid missing the top {-y} and bottom {+y} faces. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4o4a.dat''' || '''Cuboid with 4 parallel faces without bottom edges'''
|-
| [[File:box4o4a.png|200px|thumb|alt=Box4o4a]]
||This primitive represents a cuboid missing the top {-y} and bottom {+y} faces, and missing the edges of the bottom face. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4o8a.dat''' || '''Cuboid with 4 parallel faces without top and bottom edges'''
|-
| [[File:box4o8a.png|200px|thumb|alt=Box4o8a]]
|| This primitive represents a cuboid missing the top {-y} and bottom {+y} faces, and missing the edges of the top and bottom face. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4t.dat''' || '''Cuboid with 4 adjacent and all edges'''
|-
| [[File:box4t.png|200px|thumb|alt=Box4t]]
|| This primitive represents a cuboid missing the top {-y} and front {-z} faces, but with all its edges. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4-1.dat''' || '''Cuboid with 4 adjacent faces missing 1 edge'''
|-
| [[File:box4-1.png|200px|thumb|alt=Box4-1]]
||This primitive represents a cuboid missing the top {-y} and front {-z} faces and the edge between those faces. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4-2p.dat''' || '''Cuboid with 4 faces without two opposite top edges'''
|-
| [[File:box4-2p.png|200px|thumb|alt=Box4-2p]]
|| This primitive represents a cuboid missing the top {-y} and bottom {+y} faces, and missing two edges of the top face - the intersection of the two missing faces and the opposite edge. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4-3p.dat''' || '''Cuboid with 4 faces without three parallel edges'''
|-
| [[File:box4-3p.png|200px|thumb|alt=Box4-3p]]
|| This primitive represents a cuboid missing the top {-y} and bottom {+y} faces, and missing three edges of the missing faces. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4-4a.dat''' || '''Cuboid with 4 adjacent faces missing 4 edges'''
|-
| [[File:box4-4a.png|200px|thumb|alt=Box4-4a]]
||This primitive represents a cuboid missing the top {-y} and front {-z} faces and all the edges of the missing front face. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box4-7a.dat''' || '''Cuboid with 4 adjacent faces missing 7 edges'''
|-
| [[File:box4-7a.png|200px|thumb|alt=Box4-7a]]
||This primitive represents a cuboid missing the top {-y} and front {-z} faces and all the edges of both missing faces. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box3-3.dat''' || '''Cuboid with 3 adjacent faces missing 3 edges'''
|-
| [[File:box3-3.png|200px|thumb|alt=Box3-3]]
|| This primitive represents a cuboid missing the top {-y} and bottom {+y} faces, and missing three edges of the missing faces. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x} and {z} dimensions and 1LDu in the {y} dimension.
|-

|-
| '''box3-5a.dat''' || '''Cuboid with 4 adjacent faces missing 4 edges'''
|-
| [[File:box3-5a.png|200px|thumb|alt=Box3-5a]]
|| This primitive represents a cuboid missing the top {-y}, front {-z} and left {-x} faces and includes the three internal edges and the outer edges except those on the left {-z}. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x}, {y} and {z} dimensions.
|-

|-
| '''box3-7a.dat''' || '''Cuboid with 3 adjacent faces missing 7 adjacent edges'''
|-
| [[File:box3-7a.png|200px|thumb|alt=Box3-7a]]
|| This primitive represents a cuboid missing the top {-y}, front {-z} and left {-x} faces and includes the three internal edges but only the outer edges at the top (-y). Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x}, {y} and {z} dimensions.
|-

|-
| '''box3-9a.dat''' || '''Cuboid with 3 adjacent faces missing 9 adjacent edges'''
|-
| [[File:box3-9a.png|200px|thumb|alt=Box3-9a]]
|| This primitive represents a cuboid missing the top {-y}, front {-z} and left {-x} faces and includes only the three internal edges. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x}, {y} and {z} dimensions.
|-

|-
| '''box3-12.dat''' || '''Cuboid with 3 adjacent faces missing all edges'''
|-
| [[File:box3-12.png|200px|thumb|alt=Box3-12]]
|| This primitive represents a cuboid missing the top {-y}, front {-z} and left {-x} faces but excludes all edges. Its origin is the centre of the (missing) top face and by default has a size of 2LDu in each of the {x}, {y} and {z} dimensions.
|}

Primitives Reference

2023-11-27T14:52:34Z

Swampkryakwa: