[Back to Blog](/blog) # Perform Simple Editing and Saving of Autodesk® Navisworks® Files

Vadim Asandiy July 10, 2020 [\#BimNv](/blog/tag/bimnv) [\#getting started](/blog/tag/getting-started)

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NWF format files are represented in a BimNv database as an OdNwDatabase object with a container of pointers to OdNwModel objects. Each OdNwModel object contains information about models from an .nwf file:

- Path to the file
- Transformation matrix
- Linear units
- Etc.

More detailed information can be obtained from the public API of the OdNwModel class described at [docs.opendesign.com](https://docs.opendesign.com/bimnv/OdNwModel.html) (login required).

You can use the example below from the OdNwfResaver project located in Examples/OdNwfResaver/OdNwfResaver.cpp to:

- Create an OdNwDatabase object.
- Change the transformation matrix of a model.
- Change the linear units of a model.
- Add a new model to the current list of .nwf models.

#### Create an OdNwDatabase Object

Create an OdNwDatabase object corresponding to the .nwf file:

```

	 //need to read file by path from szSource
OdNwDatabasePtr pNwDb = svcs.readFile(szSource);
```

Next, make sure that the OdNwDatabase object contains NWF; for this format, the OdNwDatabase::isComposite method returns true:

```
if (pNwDb->isComposite())
```

To change properties of the model, get the object from the database. For this, use the OdNwDatabase::getModels method; if successful, OdNwDatabase::getModels method returns eOk:

```
OdArray<OdNwModelPtr> m_aModels;
if (pNwDb->getModels(m_aModels) == eOk)
```

Select the desired model, for example, according to a known index:

```
pCurrentModel = m_aModels[modelIndex]
```

#### Change the Transformation Matrix of the Model

To change the matrix, call the OdNwModel::setTransform method with the OdGeMatrix3d object as a parameter (in OdNwfResaver, an identity matrix is passed, but you can get the matrix object using the OdNwModel::getTransform method too). Perform the desired transformations on it and pass it as a parameter:

```
pCurrentModel->setTransform(OdGeMatrix3d::kIdentity);
```

#### Change Linear Units of the Model

To change the units, call the OdNwModel::setUnits method with the NwModelUnits::Enum object as a parameter:

```
pCurrentModel->setUnits(NwModelUnits::UNITS_METERS);
```

#### Add a New Model to the Current List of NWF Models

To add a model, call the OdNwDatabase::addModel method, into which you must pass a pointer to a pre-created OdNwModel object as a parameter. The OdNwModel object must contain a non-empty file path value (currently you can add these format files: .dwg, .dgn, .rfa /.rvt, .nwc/.nwd):

```
pCurrentModel = OdRxObjectImpl<OdNwModel>::createObject();
if (pCurrentModel->setSourcePath(path) == eOk)
{
  if (pNwDb->addModel(pCurrentModel) == eOk)
```

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