ALL_SF
nged
BRL-CAD
BRL-CAD User Commands

# all_sf

obtain shape factors between named regions of an entire mged database

        all_sf
        model.g
        objects

## DESCRIPTIONS

`all_sf` is an interactive program used to create a file containing shape factors between all regions of the named objects. The shape factor from region i to region j is the fraction of total energy radiated from region i that is intercepted by region j. This program finds the shapefactors for all regions in an mged model not just shapefactors between engine regions.

All_sf uses a Monte Carlo simulation, so increasing the number of significant digits in the answer by one requires about a 100-fold increase in the number of rays fired.

Three different files are created by `all_sf`: an output file, a longwave radiation exchange file, and an error file. The output file lists the shapefactors between each region. The longwave radiation exchange file is for use with PRISM. This file is not quite PRISM ready so the user must fill in the missing parameters if it is to be used with PRISM. The error file is basically used for checking errors in the program and probably will not be used by the average user.

## EXAMPLE

The following is an example from an interactive session.

    	$ all_sf con.sph.g all.air
    	Enter name of output file (25 char max).
    		cs.out
    	Enter name of longwave radiation exchange file (25 char max).
    		cs.lwx
    	Enter the name of the error file (25 char max).
    		cs.err
    	Database Title:  concentric spheres for use with
    	Number of regions:  3
    	Min & max for entire model.
    		X:  -2300.000000 - 2300.000000
    		Y:  -2300.000000 - 2300.000000
    		Z:  -2300.000000 - 2300.000000
    	Center:  0.000000, 0.000000, 0.000000

    	Radius:  3984.216857
    	Surface Area:  199478365.653926

    	Enter the number of rays to be fired.
    		50000000
    	Region names in structure.
    	Do you wish to enter your own seed (0) or use the default of 1 (1)?
    		1
    	Seed initialized
    	$

## SEE ALSO

firpass 1 , secpass 1 , showtherm 1 , ir-X 1 , ir-sgi 1 , pictx 1 , pictsgi 1 , shapefact 1 , User's Manual for IRPREP (BRL-SP-96), Computer Programs for Generating an Input File for PRISM and Displaying PRISM Results (BRL report in progress)

## AUTHOR

Susan A. Coates