3D Scene. Working with the 3D View Window |
  
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3D Scene. Working with the 3D View Window |
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The 3D view window (the 3D window) is one of the main system tools for working with the 3D model. It is used for the 3D scene rendering. The 3D window serves for viewing the model being created, as well as for selection of 3D objects for performing various manipulations with them (getting information about the selected object, editing, using as a base reference when creating operations and 3D constructions).
What is «3D Scene»?
3D scene is the entirety of all 3D objects (3D bodies and 3D constructions) that are present in the model. The size of the 3D scene is determined by the minimal cube fitting all 3D elements. When determining dimensions of the cube, the invisible 3D objects hidden from display by various methods are also included in the account.
Objects in the 3D scene are viewed using cameras. The camera that feeds the image in the 3D window, is called the active camera. By default, only the system camera is present in the model, which is located beyond the limits of the 3D scene (default camera). This is what is normally used to view the 3D scene. In most cases, just the system camera is enough for working with the 3D model. The position and orientation of the system camera can be controlled. The system camera cannot be deleted, neither can it be moved inside the 3D scene (the distance from the camera to the center of the 3D scene cannot be made less than half the 3D scene size).
In certain cases (for example, when surveying inner parts of complex 3D models or when creating animation clips) the capabilities of just the system camera may not suffice. In such cases, the user can create and use one's own cameras for setting up a view in the 3D window. Custom cameras are attached to local coordinate systems (LCS). An LCS position determines a camera position. The respective section of this chapter is devoted to working with custom cameras.
Light Sources
Illumination of bodies in the 3D scene is provided by light sources. Light sources can be divided into two main types:
•Stationary sources created by the user in the command Create Light Source. Such light sources are independent of the used camera and its position. How to create stationary light sources will be described in details in the Light sources chapter of this manual;
•Dynamic light sources, "mounted" on the active camera. The position of such light sources is defined relative to the active camera. When moving/rotating the active camera, the light sources will be also changing their position.
Dynamic light sources, as well as the visualization method, are characteristics of the 3D window, that does not depend on the used camera (whether the system or a custom one).
By default, there are two light sources in the 3D window attached to the active camera, an ambient light source (which uniformly illuminates the entire space of the 3D scene) and a directional source of white light, located on the camera. If necessary, the user can change their parameters (color, intensity, and, for a directional light - the position with respect to the camera), as well as manually create additional dynamic light sources.
Creation and editing of light sources attached to the active camera is done in the special 3D view parameters dialog. You can also specify there the background color of the 3D window (the background color does not depend on the light sources present in the 3D window). The user can select any color as the background according to one's preferences. You can use a transitional background color (with a smooth change from one color to another).
Using 3D Views
You can use the system preset 3D views for quick setup of a 3D window. 3D View is a set of information about a 3D window, including information about the parameters of the used camera, about the light sources attached to it, the current rendering method, etc.
When loading one of the 3D views stored in the system, into the current 3D window, the 3D window is automatically set up according to the data of this 3D view.
The user can edit 3D views present in the system, adding to those unique sets of data about the state of the 3D window. 3D views are handled in the special 3D view parameters dialog.
Managing 3D Window
Use the commands located in the View textual menu to manage the 3D window and the 3D scene display in it. Commands are grouped according to their purpose. Some of the commands are also available on the same-name View toolbar.
There is yet another way to call these commands. Point the mouse to a free space of the 3D window and right-click 
. The coming up context menu will contain all commands for managing the 3D window. The state of the context menu icons informs you about which mode of a particular command is currently active.
Working with Custom Cameras
Creating and using custom cameras will be described in details in the Cameras chapter. Here we will just describe general techniques of working with them.
Custom cameras are used in the cases, when the system camera is not sufficient. In such a case, the user can create one's own cameras in order to get the desired effect - for example, for surveilling inner parts of complex 3D models or creating animation clips.
The position of a custom camera is defined using an LCS. This same LCS defines the viewing direction for a custom camera. A number of parameters are defined for a camera, which define the image it yields (for example, the projecting method).
To view the 3D window from the custom, rather than the system camera, select the custom camera as the active camera of the given 3D window. This can be done in the command Select Camera.
After calling the commands, the "Select Camera" dialog window appears, which contains the list of all cameras present in the current 3D model. In it, select the camera that will be used for viewing (surveilling) the 3D scene.
When working with multiple 3D windows, an individual active camera can be specified for each window.
While working with a custom camera, you can use auto resizing of the 3D scene image, using clip plane, modify existing and create new light sources on the camera. How to move and spin the active custom camera is described in details in the "Cameras" chapter.
Working with the 3D view parameters dialog is similar to the described case of using the system camera, with one exception: the parameters pertaining to the active camera will not be available for editing in the dialog. In the case of custom cameras, these parameters are defined in the parameters dialog of the camera itself.
You cannot modify parameters of the active custom camera. If necessary, first select another camera as the active one (system or custom).
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