Live Preview, Live Nodes, and Live Update
When making changes to a network, it can be useful to get immediate feedback from each change in realtime. The Material Editor offers two features that can be enabled to give you
instantaneous feedback for your network; Live Preview, Live Nodes and Live Update.
The difference between these options may not seem apparent at first but they each perform a specific task for viewing your material in realtime.
Live Preview - This option allows for any changes to update automatically in the Material Preview window in realtime without having to use the Save or Apply buttons.
Live Node - This option allows for any constant changes that the nodes make, such as material expressions for Panners, so that they playback in realtime inside the graph.
Live Update - This option allows for each node within the network to have its shader recompiled whenever a change is made. These changes include creation of new nodes, deletion of nodes, node connections and disconnections, and changes in properties. This recompilation is necessary so that the Material Preview drawn at that node is up to date. However, recompiling these intermediate shaders can be time-consuming, especially if your Material contains a large network. If you're experiencing long wait times after every change, you may want to deactivate the Live Update option.
As an example, consider the example below, in which we have a panning texture of an awesome rocket hull being multiplied by a vector parameter, which is supplying color.
In this example, activating Live Nodes would cause the rocket texture to pan in realtime in the node's preview thumbnail in the graph. If Live Nodes were deactivated, the texture would remain stationary even though the Panner was telling it to move. You may, however, notice small updates as you move your mouse around the graph area.
If you were to change the color from cyan to purple, you would only see the change if Live Update were enabled. With Live Update disabled, the change in color would not be visible on the nodes even though the color property was indeed changed.
As an example, consider the example below, in which we have a panning texture of an awesome rocket hull being multiplied by a
vector parameter, which is supplying color.
Also, when Live Update is deactivated, you can force-update all previews manually by hitting Spacebar. Fast iteration can be achieved by disabling Live Update and then pressing
spacebar whenever you would like to view your changes.