xcmodel 3D-WEB-App v2.0

By clicking the button File, a modal window is opened for loading models to be viewed, choosing from:

• six default models of the application
• or personally uploading a file in IGES or XCModel format

The supported extensions are exclusively:

• .igs (IGES),
• .db, .dbe (XCModel).

It is possible to load multiple .db and .dbe files at once, but with each new upload, the window is refreshed, displaying only the last selection and overwriting the previous one.

By going to the 3D NURBS Models section of XCModel, you have the opportunity to download various 3D NURBS models produced with XCModel software, divided into different categories:

• Aircraft
• Animal
• Bathroom
• Boat
• Character
• Furniture
• Kitchen
• Lamp
• Music
• Other
• Plants
• Vase
• Vehicle

In the example, the Mrpotato model is downloaded from the Character category. For each model, the following are visible:

• the number of surfaces that make up the model (29)
• the number of trimmed surfaces (4)
• the total number of control points (951)

By selecting Download IGES, the single file Mrpotato.igs is downloaded, while Download XCModel OBJ allows you to download the compressed file Mrpotato.tgz.

Inside the extracted folder, the .obj file is a text document that lists the .db and .dbe files that represent the surfaces modeling the object.

• A .db file defines a NURBS surface
• A .dbe file defines a NURBS surface trimmed with the definition of a region in the parametric domain.

A .dbe file therefore represents an extension compared to .db. Additionally,

• the XCModel software allows the management of generic trimmed NURBS surfaces: the region of the parametric domain can be defined by generic 2D NURBS curves, while
• the web application is able to correctly load and display only .dbe files where the region of the parametric domain is defined by straight segments corresponding to the nodal partition of the NURBS surface.

The tools bar occupies the left part of the window. It can be shown or hidden:

• by selecting the icon with three horizontal lines
• using the T key on the keyboard if a 3d model is currently being visualized in the scene

If the display mode of the Tools panel changes, the canvas resizes dynamically to fit the screen.

The five tools can be activated either by keyboard or by mouse click.

• Lock light source: when the command is selected, the light source is fixed in a specific position relative to the scene. Moving the camera, the lighting effects on the objects change based on their position and orientation relative to the fixed light source. The direction and intensity of the light remain constant.
• Hue shift: changes the hue of the color without affecting the brightness or saturation. The effect is not visible if a texture is applied to the model.
• Fixed camera: by fixing the camera in a specific position and angle, changing the view direction (LookingAt) will change the perspective of the scene. You can shift the focus to different areas of the scene while keeping the camera position constant.
• Touch selection: if activated, it is possible to select surfaces directly by touching the canvas. It disables the commands for rotating and zooming the canvas (through touch), preventing unintended selections while moving the model using touch commands.

The application offers the possibility to view the model with

• five shaders: diffuse, phong_per_vertex, phong _per_fragment, blinn_phong and toon
• four textures: bricks, wood, metal and uv

Additional parameters that can be interacted with are:

• field of view, to modify the viewing angle of the scene from a minimum of 30 degrees to a maximum of 120
• the level of detail of the model, in a range from 1 to 16

Two different modes of RENDERING and COLORING are available. For rendering:

• SOLID, for the visualization of surfaces
• WIREFRAME, which also shows the model's bounding box

The two coloring modes are:

• MODEL, where all surfaces have a single color
• SURFACES, where each surface has a different color