# Povray

This article provides knowledge about different types of geometric primitive objects that can be exported from BRL-CAD to POV-Ray geometry file. Their properties, functions used for them, parameters are discussed in section below.

Below is the list of primitives that are working/exported correctly, partially and not touched yet.

# Arbitrary convex polyhedra

## ARB8

This primitive is formed in POV-Ray using mesh.The mesh object can be used to efficiently store large numbers of triangles. Example:

```    mesh{triangle{a,b,c}triangle{a,c,d}triangle{a,d,f}
triangle{g,h,c}triangle{e,f,g}triangle{e,g,h}}
```

## ARBN

An arbn record is specified by N sets of intersecting planes, each defined by four coefficients:

• the {X, Y, Z} coefficients of the plane's normal vector pointing outward from the center of the arbn shape, and
• the perpendicular distance of that plane from the origin.

Its exported in POV-Ray by using intersection of Planes. Example:

```    intersection{ plane{<x, y, z coefficients>, normal} .... }
```

# Ellipsoids

## ELL

This primitive is named as spheroid in POV-Ray. It is having Center Vector, Radius Vector Example:

```     Spheroid(<-1.50,3.00,-2.00>,<2.0,1.2,2.5> )
```

## ELLG, ELL1

These primitives are exported under Ell

## EHY

Elliptical Hyperboloid of BRL-CAD can be formed by POV-Ray. Currently its coordinates are exported successfully and is done by using quadric equartions of POV-Ray

## EPA

Elliptical Paraboloid in BRL-CAD. Its coordinates are exported successfully and is done by using quadric equartions of POV-Ray

## Sphere

Sphere is formed by Center and Radius Example:

```     sphere { Center, Radius [OBJECT_MODIFIERS...]}
```

# Cones and Cylinders

## Truncated General Cone

This primitive of BRL-CAD is formed by using Supercone of POV-Ray. Example:

```    Supercone( //point A, axis Ax, axis Az:<0.0,0.0,0.0>, 0.5, 1.0,
// point B, axis Bx, axis Bz:<0.0,1.5,0.0>, 0.7, 0.4)}
```

## Cone

This primitive of BRL-CAD is named as Cone in POV-Ray. It is formed as Center and radius of one end Center and radius of other end Example:

```     cone {<0, 1, 0>, 0.3  <1, 2, 3>, 1.0 texture { T_Stone25 scale 4 }}
```

## TEC

Its also exported under TGC.

## REC

Its exported nuder TGC.

## TRC

Its also under TGC

## Cylender

This is formed by Cylender of POV-Ray. center_of_one_end, center_of_other_end and Radius Example:

```     cylinder { <0, 1, 0>,<1, 2, 3>,0.5 }}
```

# Other Solids

## Torus

```    torus { 4, 1 pigment { Green }}
```

## Particle

This primitives of BRL-CAD is formed in POV-Ray by using Round_Cone2 of POV-Ray. Example:

```    Round_Cone2(
// point B, radius B:<0,1,0>, 0.40,)
```

## half

Half primitive of BRL-CAD is export into POV-Ray as Plane. Example:

```     plane { <Normal>, Distance }
```

# Primitives that are under progress

## ETO

Elliptical torus of BRL-CAD can be formed by using some methods. One of them is by using function i.e. f_torus Example:

```     f_torus(x,y,z,1*(y+0.4),0.1 )
```

## RHC

Right Hyperbolic Cylinder in BRL-CAD. Coordinates are exported successfully. It can be formed by using function

```     function { pow(x,2) + y }
```

of POV-Ray but its not working well. Its under discussion with POV-Ray community

## RPC

Right Parabolic Cylinder in BRL-CAD. Coordinates are exported successfully. It also formed by the using functions of POV-Ray but under work.