Provided by: radiance_4R1+20120125-1.1_amd64 
NAME
oconv - create an octree from a RADIANCE scene description
SYNOPSIS
oconv [ -i octree | -b xmin ymin zmin size ][ -n objlim ][ -r maxres ][ -f ][ -w ][ - ] [ input .. ]
DESCRIPTION
Oconv adds each scene description input to octree and sends the result to the standard output. Each
input can be either a file name, or a command (enclosed in quotes and preceded by a `!'). Similarly, the
octree input may be given as a command preceded by a `!'. If any of the surfaces will not fit in octree,
an error message is printed and the program aborts. If no octree is given, a new one is created large
enough for all of the surfaces.
The -b option allows the user to give a bounding cube for the scene, starting at xmin ymin zmin and
having a side length size. If the cube does not contain all of the surfaces, an error results. The -b
and -i options are mutually exclusive.
The -n option specifies the maximum surface set size for each voxel. Larger numbers result in quicker
octree generation, but potentially slower rendering. Smaller values may or may not produce faster
renderings, since the default number (6) is close to optimal for most scenes.
The -r option specifies the maximum octree resolution. This should be greater than or equal to the ratio
of the largest and smallest dimensions in the scene (ie. surface size or distance between surfaces). The
default is 16384.
The -f option produces a frozen octree containing all the scene information. Normally, only a reference
to the scene files is stored in the octree, and changes to those files may invalidate the result. The
freeze option is useful when the octree file's integrity and loading speed is more important than its
size, or when the octree is to be relocated to another directory, and is especially useful for creating
library objects for the "instance" primitive type. If the input octree is frozen, the output will be
also.
The -w option suppresses warnings.
A hyphen by itself ('-') tells oconv to read scene data from its standard input. This also implies the
-f option.
The only scene file changes that do not require octree regeneration are modifications to non-surface
parameters. If the coordinates of a surface are changed, or any primitives are added or deleted, oconv
must be run again. Programs will abort with a "stale octree" message if they detect any dangerous
inconsistencies between the octree and the input files.
Although the octree file format is binary, it is meant to be portable between machines. The only
limitation is that machines with radically different integer sizes will not work together. For the best
results, the -f option should be used if an octree is to be used in different environments.
DIAGNOSTICS
There are four basic error types reported by oconv:
warning - a non-fatal input-related error
fatal - an unrecoverable input-related error
system - a system-related error
internal - a fatal error related to program limitations
consistency - a program-caused error
Most errors are self-explanatory. However, the following internal errors should be mentioned:
Too many scene files
Reduce the number of scene files by combining them or using calls to xform(1) within files to
create a hierarchy.
Set overflow in addobject (id)
This error occurs when too many surfaces are close together in a scene. Either too many surfaces
are lying right on top of each other, or the bounding cube is inflated from an oversized object or
an improper -b specification. If hundreds of triangles come together at a common vertex, it may
not be possible to create an octree from the object. This happens most often when inane CAD
systems create spheres using a polar tessellation. Chances are, the surface "id" is near one of
those causing the problem.
Hash table overflow in fullnode
This error is caused by too many surfaces. If it is possible to create an octree for the scene at
all, it will have to be done in stages using the -i option.
EXAMPLE
To add book1, book2 and a transformed book3 to the octree ``scene.oct'':
oconv -i scene.oct book1 book2 '\!xform -rz 30 book3' > newscene.oct
AUTHOR
Greg Ward
NOTES
In the octree, the names of the scene files are stored rather than the scene information. This means
that a new octree must be generated whenever the scene files are changed or moved. Also, an octree that
has been moved to a new directory will not be able to find scene files with relative pathnames. The
freeze option avoids these problems. make(1) or rad(1) can be used to automate octree creation and
maintenance.
SEE ALSO
getbbox(1), getinfo(1), make(1), obj2mesh(1), rad(1), rpict(1), rvu(1), rtrace(1), xform(1)