[ Identification | Description | Input parameters | Links ]

The Union_mesh Component

Component for including 3D mesh in Union geometry

Identification

• Site:
• Author: Martin Olsen, and expanded upon by Daniel Lomholt Christensen
• Origin: University of Copenhagen / ACTNXT project
• Date: 17.09.18

Description

Part of the Union components, a set of components that work together and thus
separates geometry and physics within McStas.
The use of this component requires other components to be used.

1) One specifies a number of processes using process components
2) These are gathered into material definitions using Union_make_material
3) Geometries are placed using Union_box/cylinder/sphere/mesh, assigned a material
4) A Union_master component placed after all the above

Only in step 4 will any simulation happen, and per default all geometries
defined before this master, but after the previous will be simulated here.

There is a dedicated manual available for the Union_components

The mesh component loads a 3D off or stl files as the geometry.
The mesh geometry that is loaded must be a watertight mesh.
In order to check this, the component implements a simple Euler Pointcare value,
To check if the given geometry is watertight. This check is sometimes too rigid,
so a user can set the skip_convex_check parameter in order to not have this
check performed.


If you load an off file, we currently only support rank 3 polygons, i.e
triangular meshes.

It is allowed to overlap components, but it is not allowed to have two
parallel planes that coincides. This will crash the code on run time.

Input parameters

Parameters in boldface are required; the others are optional.

Name	Unit	Description	Default
filename	str	Name of file that contains the 3D geometry. Can be either .OFF, .off, .STL, or .stl	0
material_string	string	material name of this volume, defined using Union_make_material	0
priority	1	priotiry of the volume (can not be the same as another volume) A high priority is on top of low.
visualize	1	set to 0 if you wish to hide this geometry in mcdisplay	1
all_surfaces			0
cut_surface			0
target_index	1	Focuses on component a component this many steps further in the component sequence	0
target_x	m		0
target_y	m	Position of target to focus at	0
target_z	m		0
focus_aw	deg	horiz. angular dimension of a rectangular area	0
focus_ah	deg	vert. angular dimension of a rectangular area	0
focus_xw	m	horiz. dimension of a rectangular area	0
focus_xh	m	vert. dimension of a rectangular area	0
focus_r	m	focusing on circle with this radius	0
p_interact	1	probability to interact with this geometry [0-1]	0
mask_string	string	Comma seperated list of geometry names which this geometry should mask	0
mask_setting	string	"All" or "Any", should the masked volume be simulated when the ray is in just one mask, or all.	0
number_of_activations	1	Number of subsequent Union_master components that will simulate this geometry	1
skip_convex_check	1	when set to 1, skips the check for whether input .off file is convex.	0
coordinate_scale	1e-3	Multiplier that the vertex positions are multiplied by. Set to 1 for input coordinates in meters. Set to 1e-3 for input coordinates in mm.	1e-3
init	string	name of Union_init component (typically "init", default)	"init"

AT (	,	,		) RELATIVE		Generate to clipboard
ROTATED (	,	,		) RELATIVE

Links

• Source code for Union_mesh.comp.

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[ Identification | Description | Input parameters | Links ]

Generated on mcstas 3.6.1

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Last Modified: Friday, 12-Dec-2025 12:58:06 CET