In this tutorial we will bring objects into the pipeline and change some of their properties. We will also learn how to move the camera.
Loading a dataset
- First we will load one of the sample datasets into the application.
- Click on File > Open. This will display the Open File dialog where you can browse for the file to load. If you have just opened ParaViewGeo, the Filename section will include four folders; bin, examples, lib and scripts. If you don't see those folders, find the MIRARCO folder located either in your Program Files or your My Documents folder, and click on the ParaViewGeo folder within.
- Open the examples and Demo1 folders and select the Drifts.vtp file.
- Click on OK to load the file into ParaViewGeo. All supported file types can be loaded in this manner.
- The Drifts.vtp object now appears in the Pipeline Browser, but no image is visible in the View Manager. The object hasn't actually been loaded yet.
- Looking at the Object Inspector you will see the Apply button is highlighted in green. Note that there are three Point Arrays available for the drifts dataset, listed in the Array Status section. We know they are point arrays because they have a point icon instead of the cell icon.
- Use the checkmarks to decide which arrays should be loaded. For this example, we will load all three arrays, so click on Apply to finish loading the data and to show the object in the View Manager window. Each window in the View Manager is referred to as a render view.
Visualizing a Dataset
- You will now see the visualization of the Drifts dataset. When the application is initially started, the View Manager defaults to look along the -Z axis, and any datasets that are loaded appear in a gray color.
- The visibility of an object is toggled via the eye icon that appears next to the object's name in the Pipeline Browser. When the eye is a dark color, the object is visible in the render view, and when the eye is a light gray, the object is not visible.
- Click on the eye to change the visibility; make sure the dataset is visible before continuing.
- The current center of rotation is identified with the axis (shown with red and yellow lines in the image).
Controlling the Camera
- Change the look axis by clicking on the icons on the Camera Controls toolbar.
- The Reset button will change the camera zoom so that all visible objects fit into the view.
- The other six buttons change the camera angle to view along the different positive and negative axes.
- You can also change the camera angle by clicking and dragging with the mouse in the View Manager's render view. It is much easier to use an attached mouse, than to use a laptop touch-pad mouse.
- Click and drag using the left mouse button to rotate the visualization
- Scroll the middle mouse button (scroll wheel) to zoom in and out; if there is no scroll wheel, click and hold the right mouse button and drag down to zoom in and up to zoom out
- You can pan the location of the camera by clicking and holding the middle mouse button and dragging, or by holding the Shift key and using the right mouse button
- To roll the view, hold the Shift key and use the left mouse button - to yaw the view you can hold down the Ctrl key and use the right mouse button
- If these controls don't feel comfortable, you can remap the functions under Edit > Settings > Render View > Camera
- Of course a dataset doesn't have to remain gray in the render view. Click on the Display tab in the Object Inspector, and let's look at some of the properties we can change here.
- In the Color section, the default Color By option is Solid Color.
- Click on the Set Solid Color button to see a palette of basic colors. You can also create custom colors if you wish.
- Select a color and click on OK to apply the color to the drifts dataset
- We can also choose to color by one of the arrays of the dataset.
- Click on the Color By drop-down to see the available arrays; for the drifts dataset there is one cell array and three point arrays (the ones we chose to include when we loaded the data)
- Select the different arrays and see how the colors of the dataset change.
- Let's choose to color by risklevels before moving on.
Changing Display Styles
- Objects can be viewed using different representations, available in the Style section. The drifts dataset defaulted to a Surface representation. Clicking on the drop-down shows five options; Outline, Points, Wireframe, Surface and Surface with Edges.
- Try out the different options to see how the dataset changes.
- Select the Surface with Edges representation; the surface of the dataset is visible, and each cell is outlined in dark blue.
- Change the Line Width to increase or decrease the lines for each cell.
- In the Edge Style section, click on the Set Edge Color button and select a different color for the line.
- If you have your Color By set to risklevels and changed the Line Width to 2 using orange lines, this is what the drifts visualization will look like when zoomed in:
- Let's look at another object to see some of the other properties available. Right-click on the Drifts object in the Pipeline Browser and click on Delete Selected Object(s).
Creating a Source Object
- From the Sources menu, select the Wavelet option. The Object Inspector shows the properties that can be edited to create the wavelet. For now, let's use the default settings and click on Apply.
- Switch to the Display tab and look at the Style Representation options; we now have two more options available, volume and slice.
The Color Scale Editor
- Select the Volume representation; the view will show a somewhat blurry box. If you rotate the object, you will see it appears the same on all sides.
- When the representation changed to volume, Color By switched to RTData. We can change the colors that are used by clicking on the Edit Color Map button, which opens the Color Scale Editor.
- The Edit Color Map button appears whenever an array is used to color the dataset. So the Color Scale Editor can only be accessed when a point or cell array is selected in the Color By drop-down.
- The top of the editor window shows the color map that is used, and the vertical location of the nodes determines the opacity used for those colors. Nodes located at the top with an opacity at or close to 1 show a solid color, whereas nodes located at the bottom with an opacity at or close to 0 will be transparent. For the wavelet, that means that the blue sections are semi-transparent (causing the blurry effect on the box) and the red sections (located at the middle and not visible from the outside) are a solid red color when the color map shown below is used.
- To use a different color map, use the Color Space drop-down to select the name of the color scale, or click on the Choose Preset button to see a list of the available color scales together with a picture showing which colors make up the scale. You can also create you own scales and save them for later use.
- Additional nodes can be added by clicking in the map, and deleted by selecting the node and pressing "d" on the keyboard.
- The opacity can be changed by clicking on a node and dragging it up or down. (Opacity can only be changed for volume representations, but nodes can be added to the color maps for all representations).
- Add two additional nodes to the color map and drag them left and right to change how the colors align with the scalar values. Double click on a node to give it a specific color.
- The image shows the HSV color map with the two extra nodes moved towards the middle to reduce the amount of green.
- Click on the Color Legend tab and place a checkmark beside Show Color Legend; a legend now appears in the render view to show how the colors relate to the scalar values.
- Close the Color Scale Editor and change the representation to Slice; this activates the Slice section of the Display.
- With the Slice Direction drop-down we can choose which plane to use to view slices of the dataset.
- Move the Slice slider or enter a slice number to show the slice in the view.
- Try out slicing the object in the different planes.
We have now covered how to load and create objects, how to change some of their properties, and how to change the camera viewpoint in the render view.
Click on the Disconnect icon and choose Discard to clear the pipeline.