Viewing 3D Models¶

Moving, Rotating and Scaling¶

You can control the observer’s perspective in the 3D View window by moving or rotating the observation point, or by zooming in or out. Use the mouse to control these effects:

Move

move the mouse pointer over the 3D View window. Hold down the left (LMB) and right (RMB) mouse buttons simultaneously, then move the mouse to relocate the model. You can also use the middle mouse button to perform the same operation.

Rotate

move the mouse pointer over the 3D View window. While holding down LMB, move the mouse to rotate the model.

Zoom in and out

hold RMB and move the mouse. Moving left or up will zoom out, whereas moving right or down will zoom in. You can also use the mouse wheel to produce the same effect.

Setting Rotation Center¶

Figure 51. Rotation center.

When you rotate the model, the scene always turns around a certain point—the rotation center. Artec Studio will display three small coordinate axes at this point (see Figure 51.). When you launch the application, the rotation center will coincide with the origin of the main axis grid. To change its location, double-click LMB at any point on the 3D model: the rotation center will move to this point. Setting the rotation center can be useful when you wish to view a particular object from all sides. In this case, set the rotation center on the object and rotate the view using LMB.

Rendering and Shading Modes¶

The View menu allows you to choose one of the following 3D rendering options for scanned frames (see Figure 53.):

Render solid

the most common way to render with a solid fill on all faces using your selected shading method

Render wireframe

display polygonal-mesh edges without applying a solid fill to the faces

Render points

display polygonal-mesh vertices

Render wireframe over solid

apply a solid fill to the faces and use a different color to display edges. This method enables you to visually assess the quality of the polygonal model (see Mesh Simplification for details).

Render points and solid

automatically display scans in point view, but display models in solid-fill view. This mode eliminates the need to switch to another mode in order to find the best rendering approach for each surface type. It is enabled by default for the Artec Spider scanner.

You can activate any rendering mode from the 3D View toolbar. Click the button to enable solid-fill mode, to display the wireframe model, to display a point model, to display the wireframe over the solid fill and to display the point or solid-fill model, depending on the selected surfaces.

Figure 53. Available rendering modes.

For some examples of the various model-rendering modes, see Figure 54..

Figure 54. Examples of model using different rendering modes.

Point model on left and wire over solid on right.

Also, you can use the 3D View toolbar (Figure 55.) to choose a shading method for the solid fill (Figure 56.), or select one from the View menu:

Figure 55. Available shading modes.

Smooth shading ( in the toolbar)

the color value for each point in a triangular face is calculated using color interpolation at the vertices

Flat shading ( in the toolbar)

all the points on a triangular face are assigned the same color

Figure 56. Smooth versus flat shading (respectively).

Lighting, Color and Texture¶

The Lighting on option in the View menu—or the button in the toolbar—toggles the lighting in the 3D View window. This option may be useful when you must turn the lighting off to see only the outline of the model or to assess texture quality.

The Texture option in the View menu selects the method for assigning colors to the captured frames. Artec Studio offers the following methods:

• Texture—displays textured data; otherwise, the software uses the scan’s default color
• Scan color—displays the default color of the scan
• Surface color—displays each frame in a scan using a different color
• Max error—colors the frames in accordance with their registration quality; red indicates a registration error

You can choose among the above-listed options for assigning colors by clicking the corresponding button in the toolbar: , , or , respectively (see Figure 57.). Examples illustrating the different color-assignment options are shown in Figure 58..

Figure 57. Methods of assigning colors to frames.

Figure 58. Different color modes for scanned frames.

Individual color for each surface (Surface color mode) on left, highlighting registration errors (Max error mode) on right.

Back-Face Rendering¶

Artec Studio offers three methods for rendering a frame’s back face:

Show

assigns the back face the same color as the model

Cull

the back face is not displayed

Black

renders the back face in black

You can choose the mode from the View menu, or click the , or button, respectively, in the 3D View window (see Figure 59.). Black is the default mode.

Figure 59. Back-face rendering options.

See Figure 60. for examples that illustrate the different methods of back-face rendering.

Figure 60. Examples of different methods for back-face rendering.

Show back-face mode on the left, hide (Cull) in the middle and Black on the right.

Representation of Normals and Boundaries¶

The Show normals option in the View menu enables or disables rendering of normals for each vertex. By default, the normals point away from the model surface and toward the 3D scanner. You can change this direction using the Invert normals command. You can also switch between modes for displaying normals by hitting the N key with the 3D View window active.

When working with edges, the Show boundary feature in the View menu allows you to enable and disable highlighting of the model’s edges. To toggle this feature, hit the B key with the 3D View window active.

Rendering and Texturing Untextured Polygons¶

Textured models may have some untextured areas (for instance, the green area in the middle of Figure 61.). The Render polygons without texture option in the View menu allows you to toggle rendering of such areas.

Figure 61. Texture rendering for Render polygons without texture and Wrap texture coordinates options enabled or disabled.

Polygons without texture not rendered (left), rendered (middle and right) and Wrap texture coordinates turned on (right).

If the texture of the imported model is smaller than the model itself, Artec Studio can wrap it to fill the untextured areas (see Figure 61. (on right); for details on importing models, consult Importing Models and Scans). The wrapping effect is similar to floor tiling or a repeating wallpaper pattern—that is, the texture repeats periodically. To activate this option, enable the Wrap texture coordinates option in the View menu.

Displaying Boundaries of Texture Atlas¶

Textures applied to 3D models are obviously two-dimensional. You may, however, want to see the boundaries of each texture element on the actual 3D surface. Artec Studio can display a texture-atlas file, such as the the middle image in Figure 122., with its boundaries highlighted (see Figure 62.). Identifying the way in which the boundaries lie on the surface may, for example, help you determine whether you must simplify the model to get better texture application.

To enable boundary display, access the View menu and select Show texture boundaries. To disable this feature, make sure this menu command is unchecked.

Figure 62. 3D model with texture-atlas boundaries.

Technically, this command also works for textures produced by triangle methods, but it provides no usable information.

Stereo Mode¶

Stereo mode (the Enable stereo mode command in the View menu) is for operations designed to work with stereo displays and stereoscopic-3D-enabled equipment. To enable this mode, your system must support OpenGL Stereo. The Nvidia Quadro family of professional graphics cards is one example of such equipment. When stereo mode is unavailable, the menu option will be grayed out.

For more information on compatible equipment, see the Nvidia website.