﻿ View parameters

View parameters

The view shown in a 3D view window is determined by the following parameters, which can be adjusted using the view control buttons or the edit view parameters item on the view menu.

Relative to

The view parameters can be given relative to global or relative to any vessel, 6D buoy or shape object in the model. Relative to global gives the view from a fixed camera position. Relative to an object gives the view from a camera that moves with that object. This moving camera can be useful when modelling systems such as towed cases, where you want a view that tracks along with the overall movement of the model.

Size

The diameter of the view area. This is the length of the smaller of the 2 sides of the view window. This parameter must be greater than zero.

 Example: If the window on screen is wider than it is high, and view size = 100 then an object 100 units high would just fill the height of the window.

Centre

The coordinates, either global or object-relative, of the centre of the window.

Azimuth, elevation and gamma

These determine the direction (from the view centre) from which the model is viewed and the rotation about this direction. The azimuth angle is measured from the $x$ direction towards the $y$ direction of the relative-to object. The elevation angle is then measured positive upwards from there. The view shown is that seen when looking from this direction, i.e. by a viewer who is in that direction from the view centre. The gamma angle rotates about this view direction.

 Example: View elevation = +90° means looking in plan view from above, and view elevation = 0°, view azimuth = 270° (or -90°) means a standard elevation view, looking along the Y axis.

Window size

You can adjust the size of a 3D view window either by dragging the window border, or by setting its window size on the view parameters form. The latter is sometimes useful when exporting a view or exporting a replay video, since it makes it easier to export multiple files and produce videos with identical dimensions.

Graphics mode

Can be either of

• Wire frame: the model is represented using an isometric wire frame projection.
• Shaded: the model is represented as a collection of solid objects with lighting, shading, perspective and hidden line removal.

Fill mode

Available only for the shaded graphics mode. Can be either of the following:

• Solid: the mesh triangles used to represent the model are opaque, giving the effect of solid objects. (You can specify some translucency for sea surface drawing, seabed drawing and plane shapes.)
• Mesh: the mesh triangles are transparent, with only their edges visible.

The default setting is solid. The mesh option may sometimes be useful for complex models, since it gives you the ability to look inside and through objects that otherwise are solid.

Disturbance vessel

Specifies that the sea surface will be drawn as if disturbed by the presence of this vessel. If (none) is selected, or there are no vessels in the model, the sea surface will be drawn without disturbance.

Disturbance position

The position on the sea surface at which the disturbance due to a vessel will be computed. This is only required if the sea state RAOs are being interpolated on direction and period only. The reason that the position is needed is that interpolation on direction and period only requires an initial position from which to construct its direction and period interpolation grid, the same grid then being used to compute the disturbance at all other points on the sea surface.

Default view

Each model has its own default view parameters that are saved with the model data. Whenever a new 3D view is created, it starts with this default view. You can set an existing 3D view to the default view by using the reset to default view command (on the view menu or popup menu).

To set the default view parameters, first set up a 3D view to the default view that you want and then use the set as default view command (on the view menu or popup menu). You may find the calculated based on the model extent drawing option useful here, to set a default view sized such that the entire model is displayed.