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Opening and importing files
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Tetra 4D Reviewer supports the reading of multiple 3D CAD formats, some 2D CAD formats, PDFs, and
PRW files. PRW files are Tetra4D Reviewer™ session files.

You can open 3D data in new documents or import them into an existing session file.
Complex CAD files may require large amounts of memory. You can load files incrementally so that
only some chosen parts open in Tetra4D Reviewer™. This option makes the loading more efficient
and speeds up the reading process. Incremental loading is ideal if you want to work only on a few
parts of a large assembly.

Opening a CAD file from within Tetra4D Reviewer™
================================================

Computer Aided Design (CAD) applications create the 3D models, using a variety of formats. You can
view 3D models in Tetra4D Reviewer™ by opening CAD files or by importing or pasting parts from
other files.

You can open the 3D models embedded in PDF files in Tetra4D Reviewer™. If the PDF contains
multiple 3D models, you can open the models in new documents or add them to existing documents.
Tetra4D Reviewer™ doesn’t display other types of PDF content that are not within 3D models, such as
surrounding text blocks or layout graphics.
The same basic method applies whether you want to open a CAD file, a Tetra4D Reviewer™ session
file, or a 3D model embedded in a PDF.

1. Click |folder_btn| in the |logo_btn| application button and select the file.

**Note:** The Options button at the lower left of the Open dialog box opens the Preferences dialog,
providing general reading modes options as well as format specific options.

Open a PDF that contains multiple 3D models
-------------------------------------------

When you open a PDF with multiple 3D models, the document pane remains empty until you select
which model you want to load.

    1. In Tetra4D Reviewer™, button |filetree_btn| in WORKSPACE tab, if necessary.
    
    2. Expand the Files structure and the PDF folder.

    3. Right-click the model that you want to open, and choose where you want to open it:

        * Insert in Current Product: Adds the model to the current open document.
        * Create a New Product: Opens the model in a new document.


        **Note:** A PDF can include multiple 3D models and other types of content, such as ordinary graphics
        and text blocks. These other types of content do not appear when you open the file in Tetra4D
        Reviewer™.

Open a model from a “multi-model” CAD file
------------------------------------------

Some CAD formats can include multiple configurations in a file. When you open this type of multi-
configuration file in Tetra 4D Reviewer, you have first to select the model that you want to activate.

    1. If necessary, click the |filetree_btn| button in the WORKSPACE tab to open the File Tree pane.
    2. Click plus signs [+] to expand the Files Tree and access to the format of the models.

        **Note:** A number, (x), after a format name indicates the number of models in that format.

    3. Right-click the model that you want to load, and choose an option:

        * Insert in Current Product: Opens the selected model in the active document.
        * Create a New Product: Opens the selected model in a new document.


Open a 3D PDF from within Tetra4D ConverterTM
---------------------------------------------

1. In Acrobat® Pro DC/2017, activate the 3D model in the PDF.
2. Expand Tetra4D Converter™ plugin in the tools pane, then select "Edit in Tetra4D Reviewer™".

Open a file from the desktop
---------------------------

Select the file and open it:

1. Double-click to open a PRW session file.
2. Right-click another type of file with 3D content and choose Open With > Tetra4D Reviewer™
Application.

    **Note:** If the “Open with” command is not available, select Open. Then select “This Program
    From a list”, and choose Tetra4D Reviewer™.

Open a file by drag and drop
---------------------------

You can drag CAD files and PDFs with 3D content into Tetra4D Reviewer™ to open them.

1. From the desktop or Windows Explorer, drag the CAD file or the PDF into the Tetra4D Reviewer™ document pane.
2. If the Import/Open dialog box opens (because another document is open), select options:

    * Import: To add the 3D model to an already open document.
    * Open: To open the 3D model as a separate document.
    * Options: To open Preferences for Reading Mode and Read/Write CAD.
    * Always do the same action: Sets your selection of Import or Open as the default behavior for dragging files into Tetra 4D Reviewer. If selected, the Import/Open dialog box won’t appear the next time you drag a file into Tetra 4D Reviewer. 

    **Note:** You can turn off the “Always do the same” setting later by clicking it on the General tab of Preferences. 

**Opening PDF files with mixed content or multiple 3D models requires an additional step: selecting a method for opening from the File Tree context menu.**

2D files
--------

Tetra4D Reviewer™ can read some native 2D CAD files. The available features and the behavior for
2D files vary from the 3D files.
All 2D CAD file drawings open as separate documents, regardless of how you open them. A 2D file can
contain several pages, each of which appears on a separate tab in the document pane. The structure
of the 2D file appears in the Model Tree.
You can’t save 2D files as session files (PRW), but you can export them as PDF or PostScript® files.
Within Tetra4D Reviewer™, you can apply default views, select markups, show and hide certain
entities, apply colors, and take raster snapshots.
Other behaviors depend on the specific format of the read file and the features created in the
authoring application.

Import a model into an open file
--------------------------------

You can import into existing 3D files or into a new, empty document. Starting by importing into an
empty document is useful when you intend to copy and paste selected geometry from another
document.

1. Click |folder_btn| in APPLICATION button and select an existing file to open.

Note: This first file will be the target document.

2. Click |import_btn| in APPLICATION button, and select the file you want to import.
3. Select the coordinates system for the positioning of the imported model:

    * Global axis: Default option, which is the global CAD coordinate system of the active file.
    * Main axis: The activated coordinates system of the active file.


    **Note:** The added file appears in the Model Tree under Models. In the File Tree, it appears
    under the format of the CAD file.
    **Note:** You can set reading Preferences for importing some types of files. If the Options
    button is available in the Import dialog box, you can click it to open the related Preferences
    tab.

Copy and paste entities
-----------------------

Ordinary copying and pasting is a simple way to add parts to a document. You can copy and paste
parts only from one document to another, not within the same document.

1. Click |folder_btn| in APPLICATION button and select the document with the parts you want to add to another document.

2. In the first document, select the parts and click |copy_btn| in HOME tab.
3. Activate the target document where the parts will be pasted.

4. Click |paste_btn| in HOME tab.

    **Note:** If the two documents use different units, a message appears, asking if you want to
    apply the current document units to the part. If you select No, the part resizes itself so that
    the new units apply to the original size values.

Incremental loading of CAD files
================================

About incremental loading
-------------------------

The file size of complex product files can be large. Loading only the parts of the assembly needed for
your current tasks can improve performances and reduce the loading time.
You can change the loading status of individual parts and assemblies from within an open CAD file.
After you close the document as a session file (PRW) or PDF and exit Tetra4D Reviewer™, links to the
native CAD files are lost.
Further loading and unloading are no longer possible in the saved session files and PDFs.

|light_btn| Be careful about unloading parts temporarily because you want to work on another part of the
assembly. If the unloaded parts are associated with any markups or dimensions, those annotations are
lost when the part is unloaded.
Instead, save a copy of the document under a different filename or location, and then load and
unload parts before you start working on the data.

Loading parts of a 3D file
--------------------------

You can set up your Preferences to load specific types of files in two stages:

    * In the first phase, Tetra4D Reviewer™ loads only the structure of the assembly


    * In the second phase, the components or subassemblies that you select are loaded. 

This type of loading is useful to partially load a large assembly, while accessing to the full assembly structure. 

Phase 1: Load the assembly structure 
------------------------------------

To do a partial loading, you have to set up reading options before you open or import the file. These options are format- specific. The incremental loading is available only for some types of files.

1. Choose Edit > Preferences, and select the Read/Write CAD tab. 

2. In the File Formats list, select the format of the CAD file you want to open. 

3. Click Assembly to open the Assembly Options dialog box. 
    **Note:** If the Assembly button doesn’t appear, partial loading is not available for the selected format. 

4. Select Load Product Structure Only, and click OK to close the Assembly Options and Preferences. 

5. Open the file, using any method. 

At this point, no 3D window in created, because only the structure of the assembly has been read. This structure is accessible in the File Tree where a Plus sign appears aside the read format. 

Phase 2: Load selected parts and assemblies 
-------------------------------------------

In this phase, you load individual parts or subassemblies by selecting them in the loaded assembly structure. When the selected items are open, they appear in the model tree and in the document pane. 

1. If necessary, choose Workspace > File Tree. 
2. In the File Tree, click the plus signs [+] to expand the Files structure down to the loaded assembly structure. 
3. Click and Ctrl-click, as needed, to select the parts and assemblies that you want to load. 
4. Right-click the selected items in the File Tree and choose an action:

    * Insert In Current Product: Loads the items in the active document as new parts.
    * Create A New Product: Opens as a session file that you can save independently of the original file. 
    
    **Note:** The Properties command is also available on the context menu when you select only one part or assembly. Choosing Properties opens a read-only window for the selected item. 
    
All parts appear under Models in the Model Tree, but only the loaded parts have colored icons. Unloaded parts are listed with gray icons. 

In the File Tree, a dot identifies partially or fully loaded structures. A check mark appears above the icon for each loaded part. 

Phase 3: Load and unload additional parts 
-----------------------------------------

Once a part at least has been loaded, you can load other parts directly from the Model Tree. In the Model Tree, right-click an unloaded part and choose Load/Unload. 

**Note:** You can also use the process described in Phase 2 to load more parts.

Unload and reload parts
-----------------------

Unload commands appear in the Model Tree context menus for product definitions |component_btn| and assemblies |asm_btn|,. The commands don’t appear on context menus for objects |solid_btn|.

In the Model Tree, select the components that you want to unload:

    * To unload an individual instance of a part or a sub-assembly, click and Ctrl-click to select those components. Then right-click the selection and choose Load/Unload.

    * To delete all instances of specific parts or sub-assemblies, select one instance of that component. Then right- click the component and choose Unload All. 

To reload the parts, select them again in the Model Tree, right-click, and choose Load/Unload. 

Unloaded parts remain listed in both the Model Tree and File Tree, but the icons for unloaded elements are dimmed. 

**Note:** You can distinguish between unloaded items and items that are merely hidden by examining the File Tree. The icons for hidden parts are dimmed in the Model Tree but not in the File Tree.

Expand a reloaded structure
---------------------------

Special circumstances apply after you actively unload parts or assemblies. When you reload that
same item, the listing under the Model Tree doesn’t include a plus sign [+] for expanding that branch
of the Models structure.
Right-click the reloaded assembly and choose an Expand command:

* **One Level**: Shows the next tier of the assembly or part structure.


* **Component**: Expands all tiers within the selected part or assembly down to the component level.

* **All**: Expands all tiers for the selected part or assembly.


View a Properties log
---------------------

1. On the File Tree, right-click the part or assembly and choose Properties.
2. Click buttons at the bottom of the window to see information:

    * **Log (Default)**: Shows the complete information log for the part or assembly.
    * **Summary**: Shows limited information from the log.
    * **Missing File**: Generates a list of any not-found files for the selected assembly.
    * **Save**: Opens the Save As dialog box, for saving a copy of the log as a text file (.txt).


Creating and opening session files
===================================

Files you save in Tetra4D Reviewer are called session files and have the .prw extension. The PRW file
contains all the originally read CAD data. It also saves all your work on the objects and assemblies,
including any measurements, animations, or configuration views that you define.
Opening a session file from the desktop, Windows Explorer, or Start/Documents menu starts Tetra4D
Reviewer.

**Note:** The type of information that are stored in a session file corresponds to the Reading Mode
preferences that have been set to import or open the CAD file.

Save a session file
-------------------

1. Click |save_btn| or |saveas_btn| in APPLICATION button.

**Note:** If this is the first save operation with the document, the Save As dialog box opens. The
Save As dialog box contains the usual options for saving files, such as the location and
filename.

Open a session files
-------------------

To open an existing session file, do one of the following:

    * In Tetra4D Reviewer, choose File > Open; then find and select the session files that you want to open.

    * In Windows Explorer, double-click a session file. 

When you open multiple files simultaneously, each session opens as a separate document. 

**Note:** You can also drag session files from Windows Explorer into the Tetra4D Reviewer workspace.


.. |save_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/save.png

.. |saveas_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/saveas.png

.. |folder_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/p14_t2_r1_c0.png

.. |logo_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/page21_img1.png

.. |filetree_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/p13_t0_r1_c2.png

.. |import_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/p14_t2_r2_c0.png

.. |copy_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/page23_img4.png

.. |paste_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/page23_img5.png

.. |light_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/light.png

.. |asm_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/asm.png
   :height: 30px

.. |component_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/component.png
   :height: 30px

.. |solid_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/solid.png
   :height: 30px

.. |surface_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/surface.png
   :height: 30px

.. |save_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/p14_t2_r3_c0.png

.. |saveas_btn| image:: /_static/images/Tetra4D_REVIEWER_2025_Help/p14_t2_r5_c0png