Before You Edit

Researching the Model Structure and Selecting Elements

The user may often face the task of understanding the sequence of the model creation, the order in which elements and operations are calculated, and identifying relations between model elements. In particular, you may face this task if you need to modify a model created by another author. The following model research approaches are possible:

•reviewing the model structure in the model tree window;

•using the rollback function to determine the sequence of operations creation and analyzing the methods used for creating operations at various steps of model creation;

•“Destructive method”. This implies sequential deletion of operations and detailed analysis of the model at certain creation steps, identification of individual operation creation methods, experimenting with the model in various ways at its early stage of creation. We recommend doing this kind of experiments with a copy of the source file;

•going into an operation editing mode, but then canceling the editing, in order to see what elements this operation was based on and how it was created. When you enter the editing mode, the time is spent solely to calculate the rollback state, and when it is canceled, the original state is quickly restored.

3D Model Window

The 3D Model tool window serves to display the information about the 3D model structure and its creation history, as well as for selecting and managing the model elements. The 3D model tree displays all 3D construction entities and operations of the model. This information is displayed as a tree. One can select 3D elements either on the tree branches which illustrate the history of creating Bodies of the given a model, or on the auxiliary Constructions and Operations branches, where the elements are sorted by types.

The model structure can be traced by expanding the model tree branches and watching the order of operations creation. Each model tree branch represents the history of creating a certain Body of the model. Upon pointing the cursor to a 3D element name in the model tree, the respective element is highlighted in the 3D scene. If you select an operation which is buried deep in the model structure, the system will attempt to highlight in the 3D window the model topology elements (edges, faces, vertices), which were created by this operation. This is possible only if such elements are still identifiable within the final Body. Such highlighting helps to understand what part of the model is represented by a given operation. By subsequently selecting operations in the model tree, one can understand the order and the purpose of the operations. This is how you proceed with the preliminary general analysis of the model structure.

When analyzing the structure, it is helpful to know that the last operations in the creation history of the model's Body, that is the ones that are displayed in the 3D window, are by default titled in black in the model tree. Other operations are titled in blue. The names of the visible 3D construction elements are also titled in black in the 3D model tree. The invisible elements (that is, those hidden through the use of layers, the hide command or otherwise) are titled in gray in the 3D model tree. When selected in the 3D model tree or simply pointed to with the cursor, the hidden 3D elements are highlighted in the 3D scene.

Detailed information on working with the model tree can be found in the 3D Model chapter.

Rollback Model

The system provides the function of rolling back a three-dimensional model to the level of a specified operation. This functionality is helpful in the cases when it is necessary to work more on the model somewhere in the middle of the model tree, that is, revert it to an earlier creation stage.

Detailed information on rollback can be found in the Rollback Model section.

Sometimes, it is helpful to subsequently delete elements and operations in order to get a detailed understanding of the model structure as part of other experiments. In this case, the system will not be spending time for saving and rebuilding relations, unlike in a rollback. But the model itself may be damaged by this, therefore this method should be used on a copy of the source file.

Tracing parameter dependencies and relations between variables

One may often need to find out what elements directly depend on a given variable, or which geometrical or parametric relation makes the selected element interact with other objects in the model. This information is not reflected in the 3D Model window.

The Information command brings up a special dialog window in which the full model structure is displayed that pertains to all model elements. Sequences of related elements are displayed as a tree. Unlike the 3D Model window, the Information window's structure provides more details not only on 3D elements, but also on drawing elements and all auxiliary objects.

This command can be conveniently called from the context menu of the selected element of interest. In this case, the model structure in the command's window is given relative to the selected element or group of elements. The model structure can be displayed in two relational directions: Parents-Children or Children-Parents.

Detailed information on this command can be found in the Information section.

The Links command serves to trace the elements which are directly controlled by each system variable or expression that involves that variable. This command's dialog window is similar to the window of the Information command. It displays all system variables and expressions, and structural sequences of dependent elements relying on those variables and expressions.

Detailed information on this command can be found in the Links section.

Element Search

You can use the search to select an element, if you know its individual name or ID. To search for an element use the Find command.

Detailed information on this command can be found in the Find section.

Selecting elements in the 3D scene

Selecting elements in the 3D scene is described in the Selection of 3D Elements section.

Geometry Measurements and Checks

The system has various tools to perform various checks and measurements of geometrical data.

Detailed information on such tools can be found in the Model Geometry Analysis chapter.

Sometimes, to perform a series of distance measurements between various elements of a part, it may be helpful to construct a temporary 2D projection somewhere on the 2D page and create the required dimensions. Once done with measurements, you can delete that projection unless useful for other purposes.

Diagnostics Window

The “Diagnostics” tool window serves to output various system messages regarding errors in the model encountered during a recalculation, as well as warnings and information messages.The user shall be able to correctly interpret those in order to proceed with a sound and quick fix to the source of errors and restore the model validity.

Since model elements are related to each other, a failure in one element may simultaneously cause a sequence of errors in other elements. In a case like that, you need to start fixing problems from the very first failing element. Therefore, if you see several messages, first pay your attention to the beginning of the list in the upper part of the diagnostics window.

Sometimes, it is not the element triggering a recalculation error that actually needs to be fixed, but rather one of its parents. For example, a 3D profile doesn't cause regeneration errors by itself, but its geometry may not support valid calculation of a further operation. In such a case, you need to look for the reason why the 3D profile changed. Maybe, that reason originates on the workplane page that contains the source construction for the profile. After that, the error in the child 3D element may disappear automatically.

Working with the diagnostics may be enhanced by using the 3D model tree for finding the desired element. The model elements within which errors are detected are marked by special signs:

•A red cross on an element's icon (, , ) means the failure occurred in that particular element.

•A red arrow on an element's icon (, , , , ) means an error was detected among its parents. By tracing the history of the element's creation along the model tree branch, you can reach the first failing element. If there are errors, then the red arrow is also show on special folders of the model tree containing lists of elements (, ).

•A blue cross on an element's icon () means an operation was suppressed by the user. This is just an info message, rather than an error.

To reach the failing element, you need to expand the branches of the model tree and follow the tree structure, finding the marked elements.