Primitives Reference
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:
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.
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.
| rect.dat | Rectangle with all edges |
 |
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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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. |
| box.dat | Cuboid with all faces and edges |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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. |