File Solid

Solid with properties derived from CAD file

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Libraries:
Simscape / Multibody / Body Elements

Description

The File Solid block models a solid with geometry, inertia, color, and reference frame derived from a CAD file. You can manually specify the inertia and color for the imported solid. The File Solid block can model a solid by using various CAD formats.

Supported Software and File Formats

CAD	Release Supported
ACIS	Up to 2020
Autodesk® Inventor	Up to 2022
CATIA V4	Up to 4.2.5
CATIA V5	Up to V5-6 R2021
CATIA V6	Up to V5-6 R2019(R29)
Creo-Pro/E	Pro/Engineer 19.0 to Creo 8.0
IGES	5.1, 5.2, and 5.3
JT	Up to v10.5
NX	V11.0 to NX 18.0, NX to NX12, NX 1847 Series to NX 1980 Series
OBJ	All Versions
Parasolid	Up to v33
PRC	All Versions
Rhino3D	4 to 7
Solid Edge	V19 - 20, ST - ST10, 2021
SolidWorks®	97 to 2021
STEP	AP 203 E1/E2, AP 214, and AP 242
STL	All Versions
U3D	ECMA-363

Note

The block cannot read CAD drawings because they do not contain the necessary data for a solid.

Import Parts

The File Solid block represents the imported part as a rigid body. The block can read the inertia and color data from the CAD file. Alternatively, you can explicitly specify these properties for the imported parts. For more information, see Inertia and Graphic.

The File Solid block uses the inertia frame, whose origin is coincident with the center of mass and axes are parallel to the axes of the reference frame, to compute the inertia of the imported solid. The frame in which the moments and products of inertia are computed varies among CAD software. For more information about how to specify the inertia, see Specifying Custom Inertias.

Calculate Inertia

If the block computes the inertia according to the geometry of the imported body, you can see the computed values in the block dialog box. Expand the Derived Values node under Inertia and click Update. If the geometry, density, or mass changes, click the Update button to compute the inertia again. All the computed values are in SI units.

Frames

The imported bodies connect through frames. By default, the imported body has a reference frame represented by port R. The CAD file specifies the location of the reference frame.

If you need to have the connection on a different part of the body or if you need to have multiple connections on the body, you can create additional frames on the body. Each frame adds a new frame port to the block. For more information about creating custom frames, see Frames.

Import Assemblies

The File Solid block represents the imported assembly as a single rigid body using the default pose specified in the CAD file. The block ignores all the constraints in the CAD file and assumes that the whole assembly has one density.

The File Solid block can read density data from the CAD file if you, under Inertia, specify Type as Calculate From Geometry and Based On as Density. To ensure that the block successfully reads the density, the CAD file must have a density for the whole assembly and the densities of all the parts must either have the same value or be unspecified. Otherwise, the simulation returns an error.

You can manually specify the density, mass, or inertia properties of the imported assembly. The process is the same as the process for a single part. For more information, see Specifying Custom Inertias.

You can import an assembly that has parts represented by different modeling methods, such as faceted, polygonal, and BRep models. However, you can create frames only on parts represented by BRep models because they have the necessary boundary primitives, such as points, edges, and faces.

Export Geometry

The File Solid block can generate a convex hull geometry representation of an imported CAD file in the Simscape Multibody environment. You can use the exported geometry for spatial contacts.

As shown in the figure, the convex hull geometry is an approximation of the true geometry. The block calculates the physical properties, such as mass and inertia, based on its true geometry.

Examples

Cartesian 3-D Printer

Models a Cartesian 3-D printer. The model allows you to specify the rotational motion of the motor on each axis to define a printing path. In this example, the printing head moves along the edges of two letters, S and M, using the predefined rotational motions.

• Open Model

Tower Crane with Trolley and Hoist

Models a tower crane with a trolley and a hoist. The hoist can raise and lower a load, and the trolley moves the load towards and away from the tower. Blocks from the belts and cables library are used to model the pulleys that control lifting the load and moving the trolley.

• Open Model

Limitations

On Mac, the visualization pane runs slow if the generated geometry has a large number of triangles or vertices. To mitigate this issue, you can use CAD files with less vertices.

Ports

Frame

R — Local reference frame

frame

Local reference frame of the imported solid. This frame is fixed with respect to the solid. Connect this frame to another block to specify the location and orientation of the solid.

Geometry

CH — Convex hull representation

geometry

Convex hull that represents the geometry of the solid. Connect this port to a Spatial Contact Force block to model contacts on the convex hull.

Dependencies

To enable this port, under Geometry, expand Export and select Convex Hull.

Parameters

Geometry

File Name — Path of CAD file

custom character vector

Path of the CAD file, specified as a custom character vector. The file location can be specified as an absolute path starting from the root directory of the file system or a relative path starting from a folder on the MATLAB^® path.

See Supported Software and File Formats for details of supported file formats.

Example: 'C:/Users/JDoe/Documents/myShape.STEP' or 'Documents/myShape.STEP'

Unit Type — Source for solid geometry units

From File (default) | Custom

Source of the solid geometry units. Select From File to use the units specified in the imported file. Select Custom to specify your own units.

Unit — Length units in which geometry coordinates are specified in the imported file

m (default) | cm | mm | km | in | ft

Length units in which to interpret the geometry defined in a geometry file. Changing the units changes the scale of the imported geometry.

Convex Hull — Generate a convex hull representation of the true geometry

off (default) | on

Select Convex Hull to generate a convex hull representation of the true geometry. Select this parameter enables the port CH.

Inertia

Type — Inertia parameterization to use

Calculate from Geometry (default) | Point Mass | Custom

Inertia parameterization to use. Select Point Mass to model a concentrated mass with negligible rotational inertia. Select Custom to model a distributed mass with the specified moments and products of inertia. The default setting, Calculate from Geometry, enables the block to automatically calculate the rotational inertia properties from the solid geometry and either density or mass.

Based on — Parameter to use in inertia calculation

Density from File (default) | Custom Density | Custom Mass

Parameter to use in inertia calculation. The block calculates the inertia tensor from the solid geometry and the parameter selected.

• Density from File: The block calculates the inertia of the body based on the density obtained from the CAD file. Note that only some CAD formats contain density data.

• Custom Density: The block calculates the inertia of the body based on the density specified in the dialog box.

• Custom Mass: The block calculates the inertia of the body based on the mass specified in the dialog box.

Density — Mass per unit volume of material

1000 kg/m^3 (default)

Mass per unit volume of material. The mass density can take on a positive or negative value. Specify a negative mass density to model the effects of a void or cavity in a solid body.

Dependencies

To enable this parameter, set:

1. Type to Calculate from Geometry

2. Based on to Custom Density

Mass — Total mass of the solid element

1 kg (default) | scalar with units of mass

Total mass to attribute to the solid element. This parameter can be positive or negative. Use a negative value to capture the effect of a void or cavity in a compound body (one comprising multiple solids and inertias), being careful to ensure that the mass of the body is on the whole positive.

Center of Mass — Center-of-mass coordinates

[0 0 0] m (default) | three-element vector with units of length

[x y z] coordinates of the center of mass relative to the block reference frame.

Dependencies

To enable this parameter, set Type to Custom.

Moments of Inertia — Diagonal elements of inertia tensor

[1 1 1] kg*m^2 (default) | three-element vector with units of mass*length^2

Three-element vector with the [I_xx I_yy I_zz] moments of inertia specified relative to a frame with origin at the center of mass and axes parallel to the block reference frame. The moments of inertia are the diagonal elements of the inertia tensor

$$\left(\begin{array}{ccc}{I}_{xx}& & \\ & I_{yy}& \\ & & I_{zz}\end{array}\right),$$

where:

• $$I_{xx}={\displaystyle \underset{m}{\int }\left(y^2+z^2\right)dm}$$

• $$I_{yy}={\displaystyle \underset{m}{\int }\left(x^2+z^2\right)dm}$$

• $$I_{zz}={\displaystyle \underset{m}{\int }\left(x^2+y^2\right)dm}$$

Dependencies

To enable this parameter, set Type to Custom.

Products of Inertia — Off-diagonal elements of inertia tensor

[0 0 0] kg*m^2 (default) | three-element vector with units of mass*length^2

Three-element vector with the [I_yz I_zx I_xy] products of inertia specified relative to a frame with origin at the center of mass and axes parallel to the block reference frame. The products of inertia are the off-diagonal elements of the inertia tensor

$$\left(\begin{array}{ccc}& I_{xy}& I_{zx}\\ I_{xy}& & I_{yz}\\ I_{zx}& I_{yz}& \end{array}\right),$$

where:

• $$I_{yz}=-{\displaystyle \underset{m}{\int }yzdm}$$

• $$I_{zx}=-{\displaystyle \underset{m}{\int }zxdm}$$

• $$I_{xy}=-{\displaystyle \underset{m}{\int }xydm}$$

Dependencies

To enable this parameter, set Type to Custom.

Derived Values — Display of calculated values of inertia properties

button

Display of the calculated values of the solid inertia properties—mass, center of mass, moments of inertia, and products of inertia. Click the Update button to calculate and display the properties of the solid. Click this button following any changes to the block parameters to ensure that the displayed values are still current.

The center of mass is resolved in the local reference frame of the solid. The moments and products of inertia are each resolved in the inertia frame of resolution—a frame whose axes are parallel to those of the reference frame but whose origin coincides with the solid center of mass.

Dependencies

To enable this parameter, set Type to Calculate from Geometry.

Graphic

Type — Graphic to use for visualization

From Geometry (default) | Marker | None

Type of the visual representation of the solid, specified as From Geometry, Marker, or None. Set the parameter to From Geometry to show the visual representation of the solid. Set the parameter to Marker to represent the solid as a marker. Set the parameter to None to hide the solid in the model visualization.

Visual Properties — Parameterizations for color and opacity

Simple (default) | Advanced

Parameterizations for specifying visual properties. Select Simple to specify Diffuse Color and Opacity. Select Advanced to specify more visual properties, such as Specular Color, Ambient Color, Emissive Color, and Shininess.

Dependencies

To enable this parameter, set Type to From Geometry or Marker.

Shape — Shape of marker to represent to the solid

Sphere (default) | Cube | Frame

Shape of the marker by means of which to visualize the solid. The motion of the marker reflects the motion of the solid itself.

Dependencies

To enable this parameter, set Type to Marker.

Size — Width of the marker in pixels

10 pixels (default) | scalar

Width of the marker in pixels. This width does not scale with zoom level. Note that the apparent size of the marker depends partly on screen resolution, with higher resolutions packing more pixels per unit length, and therefore producing smaller icons.

Dependencies

To enable this parameter, set Type to Marker.

Color — Color of light due to diffuse reflection

[0.5 0.5 0.5] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1 | 4-by-1 or 1-by-4 vector with values in the range of 0 to 1

Color of the graphic under direct white light, specified as an [R G B] or [R G B A] vector on a 0–1 scale. An optional fourth element (A) specifies the color opacity on a scale of 0–1. Omitting the opacity element is equivalent to specifying a value of 1.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Simple

Opacity — Graphic opacity

1.0 (default) | scalar in the range of 0 to 1

Graphic opacity, specified as a scalar in the range of 0 to 1. A scalar of 0 corresponds to completely transparent, and a scalar of 1 corresponds to completely opaque.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Simple

Diffuse Color — Color of light due to diffuse reflection

[0.5 0.5 0.5] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1 | 4-by-1 or 1-by-4 vector with values in the range of 0 to 1

Color of the light due to diffuse reflection, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

The diffuse color reflects the main color of the rendered solid and provides shading that gives the rendered object a three-dimensional appearance.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Advanced

Specular Color — Color of light due to specular reflection

[0.5 0.5 0.5 1.0] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1 | 4-by-1 or 1-by-4 vector with values in the range of 0 to 1

Color of the light due to specular reflection, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1. This parameter changes the color of the specular highlight, which is the bright spot on the rendered solid due to the reflection of the light from the light source.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Advanced

Ambient Color — Color of ambient light

[0.15 0.15 0.15 1.0] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1 | 4-by-1 or 1-by-4 vector with values in the range of 0 to 1

Color of the ambient light, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

Ambient light refers to a general level of illumination that does not come directly from a light source. The Ambient light consists of light that has been reflected and re-reflected so many times that it is no longer coming from any particular direction. You can adjust this parameter to change the shadow color of the rendered solid.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Advanced

Emissive Color — Self-illumination color

[0.0 0.0 0.0 1.0] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1

Color due to self illumination, specified as an [R,G,B] or [R,G,B,A] vector in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

The emission color is color that does not come from any external source, and therefore seems to be emitted by the solid itself. When a solid has an emissive color, the solid can be seen even if there is no external light source.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Advanced

Shininess — Highlight sharpness

75 (default) | scalar with value constrained to 0–128

Sharpness of specular light reflections, specified as a scalar number on a 0–128 scale. Increase the shininess value for smaller but sharper highlights. Decrease the value for larger but smoother highlights.

Dependencies

To enable this parameter, set:

1. Type to From Geometry or Marker

2. Visual Properties to Advanced

Frames

Show Port R — Show reference frame port for connection to other blocks

on (default) | off

Select to expose the R port.

New Frame — Create custom frame for connection to other blocks

button

Click the Create button to open a pane for creating a new body-attached frame. In this pane, you can specify the name, origin, and orientation for the frame.

• To name the custom frame, click the text field of the Frame Name parameter. The name identifies the corresponding port on the solid block and in the tree view pane of the Mechanics Explorer.

• To select the Frame Origin of the custom frame, use one of the following methods:

  • At Reference Frame Origin: Make the new frame origin coincident with the origin of the reference frame of the solid.

  • At Center of Mass: Make the new frame origin coincident with the center of mass of the solid.

  • Based on Geometric Feature: Make the new frame origin coincident with the center of the selected feature. Valid features include surfaces, lines, and points. Select a feature from the visualization pane, then click Use Selected Feature to confirm the location of the origin. The name of the origin location appears in the field below this option.

• To define the orientation of the custom frame, under the Frame Axes section, select the Primary Axis and Secondary Axis of the custom frame and then specify their directions.

  Use the following methods to select a vector for specifying the directions of the primary and secondary axes. The primary axis is parallel to the selected vector and constrains the remaining two axes to its normal plane. The secondary axis is parallel to the projection of the selected vector onto the normal plane.

  • Along Reference Frame Axis: Selects an axis of the reference frame of the solid.

  • Along Principal Inertia Axis: Selects an axis of the principal inertia axis of the solid.

  • Based on Geometric Feature: Selects the vector associated with the chosen geometry feature of the solid. Valid features include surfaces and lines. The corresponding vector is indicated by a white arrow in the visualization pane. You can select a feature from the visualization pane and then click Use Selected Feature to confirm the selection. The name of the selected feature appears in the field below this option.

FrameN — Edit or delete existing custom frame

frame name

Frames that you have created. N is a unique identifying number for each custom frame.

• Click the text field to edit the name of an existing custom frame.

• Click the Edit button to edit other aspects of the custom frame, such as origin and axes.

• Click the Delete button to delete the custom frame.

Dependencies

To enable this parameter, create a frame by clicking New Frame.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2018b

R2023b: Import assemblies

You can now import assemblies to the File Solid block from various CAD formats. The File Solid block represents the imported assembly as a single rigid body using the default pose in the CAD file. The block ignores all the constraints and assumes that the whole geometry has one density. The block can obtain the density from the CAD file if the densities of all the parts are the same. If the assembly file does not have a density or has multiple densities, you must explicitly specify the inertia properties for the assembly.