JT Reader

The JT Reader provides full access to the Assembly, Visualization, B-rep and View & PMI Data stored within a particular JT file. A file does not need to have a particular extension to be read correctly by HOOPS Exchange however the file extension of JT files that you can expect to be loaded by HOOPS Exchange is:

Our readers are updated to the latest released version within 90 days of the release of the authoring software. You can see the exact version supported in the current release here.

Assembly

The assembly can be defined in a series of files or in a single monolithic file. Full support for the layer and filter information is included. Incremental load is not supported by our JT reader.

B-rep

A JT file can contain three different types of B-rep data: Parasolid B-rep, JT B-rep, or ULP (Ultra-Lightweight Precise) B-rep. We currently support all three types. However, our JT reader does not support ULP B-rep for JT 10 files.

The JT B-rep is relatively simple and only supports geometry in NURBS form. The only types of surface and curve geometry that can be found in a JT B-rep is:

The Parasolid B-rep is not restricted and can be anything from the official Parasolid B-rep. The geometry available is also listed in the Parasolid section but for completeness it is included here. The list of surface types available in Parasolid B-rep is:

The list of curve types available in Parasolid B-rep is:

Visualization

We fully support the loading of tessellated objects from a JT file. HOOPS Exchange can load the different LODs and the developer instructs HOOPS Exchange which LOD to load via the "level of detail" reading option. Support is provided for tessellated wireframes and point clouds.

HOOPS Exchange also handles Primitive Set Shape. These are boxes, cylinders, pyramids, spheres, and prisms stored in the file with the minimum data necessary to procedurally generate them.

Views

Full support for views including the visibilities of objects associated to views is supported.

PMI

The JT reader provides access to the PMI information to the full extent of the JT specification. HOOPS Exchange is able to retrieve the link between PMI data and the geometry.

The different PMI types available in JT are:

* The JT file format does not support the concept of semantic PMI.

Miscellaneous

All the properties and meta-data contained in a file are exposed to the user.

Import options specific to JT

None

Limitations

Our JT reader has the following limitations: