ParaViewGeo contains a linking feature that allows you to link objects or properties. These links can be managed via the Link Manager, available under Tools > Manage Links. Two kinds of links can be created; Object Links and Property Links.
The advantage of the Link Manager is that it lists all the links that currently exist in the application.
One of the link modes available is the Object Link. Below are two identical tree views that allow you to select which objects will be linked. While in this mode, the tree structure contains two main sections, Views and Objects.
Linking Views through the Manage Links section will create camera links. One method of creating camera links is explained on the View Manager page, and these same links can be created through the Link Manager.
To use the Link Manager to create camera links, click on Tools > Manage Links and then click Add to open the Add Link window. Enter a name for the link (optional) and expand the Views section on the left tree view. Listed underneath are all the render views that currently exist in your session. Select one of the render views, then expand the Views section on the right side and select the render view you want to link with. Click on OK to create the link, and then close the Link Manager window. Now any camera changes made in one of the views will be mimicked in the other view.
You might want to use the Link Manager to create your camera views to ensure that all links are created, since the View Manager will not indicate which views are linked to each other. Note that camera links created in the View Manager by default are called CameraLink#, whereas links created in the Link Manager default to Link#.
The Objects section of the tree view lists all of the objects that exist in the pipeline. You can link two objects together so that changes made to one will also be reflected in the other object. This applies to the object properties, not to options such as coloring or style representation, and the properties must be available to both objects.
For instance, you can create two boxes in the render view, one with center 0,0,0 and colored red, the other with center 1,1,1 and colored blue. Now link the boxes by opening the Link Manager and choosing the Add button. On the Add Link window, open the Objects section in the left view and select the first box, then open the Objects section in the right view and select the other box. Click on OK and then close the Link Manager window.
If you now change the X Length of one of the boxes to 1.5 and apply the change, you will notice that both boxes increase in the X direction. If you make a change to the Center of one box, the same change is applied to the other box, and they will be on top of each other (assuming all other property values are the same).
If you create this kind of link between two different objects, such as a box and a sphere, only those properties that are shared between both objects will be linked. So changing the X Length on the box will not have an effect on the Sphere, and the same is true for changing the radius on the sphere, since the box doesn't have a radius. However, if the two are linked and the center is changed on one, the other will have that same center applied.
ParaViewGeo allows you to link two filters together, so that changes made to one filter are also applied to the other. This type of linking works with several of the available filters, and the filters don't have to be identical to be linked.
To give a simple example, let's create a Box and a Sphere using the Sources menu. You can color the datasets if you wish, it may be easier to see the effect if both objects are not the default white.
Apply a Clip filter to each object using the default Plane clip type; the clip planes do not need to be identical. To link the filters, open the Link Manager and then click the Add button to open the Add Link window. You can enter a Name for the link if you wish. Below are two identical tree views that allow you to select which objects will be linked. On the left side, expand the Clip1 section and click on the Plane object. On the right side, click on Plane under Clip2, click on OK to create the link and then close the Link Manager window.
Now that the planes are linked, click the edge of one of the planes (outlined in red) and drag it to increase or decrease the size of the clip and click Apply. Notice that the plane of the second object moved as well, keeping the angle that was originally applied. In the image below, the sphere (in white) was clipped vertically, and the box (colored in TCoords) was clipped at an angle. The centers of the planes are linked and maintain their position. However, if instead of sliding the plane you choose to change the angle of the plane (using the arrow normal), both planes will adjust to using that angle.
The filters that are linked do not need to be identical filters. For instance, instead of using 2 clip filters, you could have used a Slice filter on one of the objects and then linked the plane of the clip to the plane of the slice, as was done in this image.
Selecting the Property Link mode in the Add Link window will cause the lower section of the window to divide into four sections.
By using the Property Link mode, you can choose to link specific object properties, even if they are not the same. As an example, let's again use a Box and a Sphere. Open the Link Manager, and click on the Add button to open the Add Link window. Change the Mode to Property Link, and then expand the Objects section in the left tree and click on the Box object. Notice that the area underneath now shows the properties available for the Box. In the right tree, expand the Objects section and click on the Sphere to display the sphere's properties underneath.
The brackets behind the property name indicate the type of input that is used and the number of values. The XLength uses one real number, whereas the Center property has three real numbers, and the ThetaResolution uses one integer. You cannot create links between properties that have different inputs, and if selected, the OK button will be grayed out. But we could, for example, create a link between the XLength of the box and the Radius of the sphere. Once the two properties are selected, click on OK and then close the Link Manager window.
To test the link, change the radius of the sphere to 1.5 and click Apply. You may have to change the Style Representation to wireframe if both use the same center, but note that when the radius changed, the X length of the box also changed to that value.
Links that have already been created can be modified or removed at any time.
To modify a link, open the Link Manager and select the link from the list, then click on the Edit button on the right. The Edit Links window appears, and you can change which objects / properties are linked using the left and right tree views.
To remove a link, select the link in the list on the Link Manager window and click on the Remove button on the right. Once a link is removed, the Undo button can not recreate it.
Links will be automatically removed from the list if one of the objects (views, filters and dataset objects) that is used in the link is removed.