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-- File: BRepGProp.cdl
-- Created: Fri Dec 4 16:56:29 1992
-- Author: Isabelle GRIGNON
-- <isg@sdsun2>
---Copyright: Matra Datavision 1992
package BRepGProp
---Purpose: Provides global functions to compute a shape's global
-- properties for lines, surfaces or volumes, and bring
-- them together with the global properties already
-- computed for a geometric system.
-- The global properties computed for a system are :
-- - its mass,
-- - its center of mass,
-- - its matrix of inertia,
-- - its moment about an axis,
-- - its radius of gyration about an axis,
-- - and its principal properties of inertia such as
-- principal axis, principal moments, principal radius of gyration.
uses GProp,
BRepAdaptor,
BRepTools,
BRep,
TopExp,
TopoDS,
Geom2dAdaptor,
gp,
GeomAbs,
TColStd
is
class EdgeTool;
class Face;
class Domain;
class Cinert instantiates CGProps from GProp( Curve from BRepAdaptor,
EdgeTool from BRepGProp);
class Sinert instantiates SGProps from GProp( Edge from TopoDS,
Face from BRepGProp ,
Domain from BRepGProp);
class Vinert instantiates VGProps from GProp( Edge from TopoDS,
Face from BRepGProp,
Domain from BRepGProp);
class VinertGK instantiates VGPropsGK from GProp( Edge from TopoDS,
Face from BRepGProp,
Domain from BRepGProp);
--
-- Package methods to compute global properties.
--
LinearProperties(S : Shape from TopoDS; LProps : in out GProps from GProp);
---Purpose: Computes the linear global properties of the shape S,
-- i.e. the global properties induced by each edge of the
-- shape S, and brings them together with the global
-- properties still retained by the framework LProps. If
-- the current system of LProps was empty, its global
-- properties become equal to the linear global
-- properties of S.
-- For this computation no linear density is attached to
-- the edges. So, for example, the added mass
-- corresponds to the sum of the lengths of the edges of
-- S. The density of the composed systems, i.e. that of
-- each component of the current system of LProps, and
-- that of S which is considered to be equal to 1, must be coherent.
-- Note that this coherence cannot be checked. You are
-- advised to use a separate framework for each
-- density, and then to bring these frameworks together
-- into a global one.
-- The point relative to which the inertia of the system is
-- computed is the reference point of the framework LProps.
-- Note: if your programming ensures that the framework
-- LProps retains only linear global properties (brought
-- together for example, by the function
-- LinearProperties) for objects the density of which is
-- equal to 1 (or is not defined), the function Mass will
-- return the total length of edges of the system analysed by LProps.
-- Warning
-- No check is performed to verify that the shape S
-- retains truly linear properties. If S is simply a vertex, it
-- is not considered to present any additional global properties.
SurfaceProperties(S : Shape from TopoDS; SProps : in out GProps from GProp);
---Purpose: Computes the surface global properties of the
-- shape S, i.e. the global properties induced by each
-- face of the shape S, and brings them together with
-- the global properties still retained by the framework
-- SProps. If the current system of SProps was empty,
-- its global properties become equal to the surface
-- global properties of S.
-- For this computation, no surface density is attached
-- to the faces. Consequently, the added mass
-- corresponds to the sum of the areas of the faces of
-- S. The density of the component systems, i.e. that
-- of each component of the current system of
-- SProps, and that of S which is considered to be
-- equal to 1, must be coherent.
-- Note that this coherence cannot be checked. You
-- are advised to use a framework for each different
-- value of density, and then to bring these
-- frameworks together into a global one.
-- The point relative to which the inertia of the system
-- is computed is the reference point of the framework SProps.
-- Note : if your programming ensures that the
-- framework SProps retains only surface global
-- properties, brought together, for example, by the
-- function SurfaceProperties, for objects the density
-- of which is equal to 1 (or is not defined), the
-- function Mass will return the total area of faces of
-- the system analysed by SProps.
-- Warning
-- No check is performed to verify that the shape S
-- retains truly surface properties. If S is simply a
-- vertex, an edge or a wire, it is not considered to
-- present any additional global properties.
SurfaceProperties(S : Shape from TopoDS; SProps : in out GProps from GProp;
Eps: Real) returns Real;
---Purpose: Updates <SProps> with the shape <S>, that contains its pricipal properties.
-- The surface properties of all the faces in <S> are computed.
-- Adaptive 2D Gauss integration is used.
-- Parameter Eps sets maximal relative error of computed mass (area) for each face.
-- Error is calculated as Abs((M(i+1)-M(i))/M(i+1)), M(i+1) and M(i) are values
-- for two successive steps of adaptive integration.
-- Method returns estimation of relative error reached for whole shape.
-- WARNING: if Eps > 0.001 algorithm performs non-adaptive integration.
------------------------
-- VolumeProperties --
------------------------
---Purpose:
-- Computes the global volume properties of the solid
-- S, and brings them together with the global
-- properties still retained by the framework VProps. If
-- the current system of VProps was empty, its global
-- properties become equal to the global properties of S for volume.
-- For this computation, no volume density is attached
-- to the solid. Consequently, the added mass
-- corresponds to the volume of S. The density of the
-- component systems, i.e. that of each component of
-- the current system of VProps, and that of S which
-- is considered to be equal to 1, must be coherent to each other.
-- Note that this coherence cannot be checked. You
-- are advised to use a separate framework for each
-- density, and then to bring these frameworks
-- together into a global one.
-- The point relative to which the inertia of the system
-- is computed is the reference point of the framework VProps.
-- Note: if your programming ensures that the
-- framework VProps retains only global properties of
-- volume (brought together for example, by the
-- function VolumeProperties) for objects the density
-- of which is equal to 1 (or is not defined), the
-- function Mass will return the total volume of the
-- solids of the system analysed by VProps.
-- Warning
-- The shape S must represent an object whose
-- global volume properties can be computed. It may
-- be a finite solid, or a series of finite solids all
-- oriented in a coherent way. Nonetheless, S must be
-- exempt of any free boundary. Note that these
-- conditions of coherence are not checked by this
-- algorithm, and results will be false if they are not respected.
VolumeProperties(S : Shape from TopoDS; VProps : in out GProps from GProp;
OnlyClosed: Boolean = Standard_False);
VolumeProperties(S : Shape from TopoDS; VProps : in out GProps from GProp;
Eps: Real; OnlyClosed: Boolean = Standard_False) returns Real;
---Purpose: Updates <VProps> with the shape <S>, that contains its pricipal properties.
-- The volume properties of all the FORWARD and REVERSED faces in <S> are computed.
-- If OnlyClosed is True then computed faces must belong to closed Shells.
-- Adaptive 2D Gauss integration is used.
-- Parameter Eps sets maximal relative error of computed mass (volume) for each face.
-- Error is calculated as Abs((M(i+1)-M(i))/M(i+1)), M(i+1) and M(i) are values
-- for two successive steps of adaptive integration.
-- Method returns estimation of relative error reached for whole shape.
-- WARNING: if Eps > 0.001 algorithm performs non-adaptive integration.
-- ----------------------------------------------------------------------------------------
VolumePropertiesGK(S : Shape from TopoDS;
VProps : in out GProps from GProp;
Eps : Real from Standard = 0.001;
OnlyClosed: Boolean from Standard = Standard_False;
IsUseSpan : Boolean from Standard = Standard_False;
CGFlag : Boolean from Standard = Standard_False;
IFlag : Boolean from Standard = Standard_False)
returns Real;
---Purpose: Updates <VProps> with the shape <S>, that contains its pricipal properties.
-- The volume properties of all the FORWARD and REVERSED faces in <S> are computed.
-- If OnlyClosed is True then computed faces must belong to closed Shells.
-- Adaptive 2D Gauss integration is used.
-- Parameter IsUseSpan says if it is necessary to define spans on a face.
-- This option has an effect only for BSpline faces.
-- Parameter Eps sets maximal relative error of computed property for each face.
-- Error is delivered by the adaptive Gauss-Kronrod method of integral computation
-- that is used for properties computation.
-- Method returns estimation of relative error reached for whole shape.
-- Returns negative value if the computation is failed.
VolumePropertiesGK(S : Shape from TopoDS;
VProps : in out GProps from GProp;
thePln: Pln from gp;
Eps : Real from Standard = 0.001;
OnlyClosed: Boolean from Standard = Standard_False;
IsUseSpan : Boolean from Standard = Standard_False;
CGFlag : Boolean from Standard = Standard_False;
IFlag : Boolean from Standard = Standard_False)
returns Real;
end BRepGProp;
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