Debugging ICE Trees

To show port values

1. Do one of the following:

   • Middle-click on a connection.

   • Right-click over a connection or input port and choose Show Values.

2. If you haven't displayed the selected port values before, the Show Values dialog box opens. Specify the desired display options and click OK. See AttributeDisplay Property Editor [Properties Reference].

   Otherwise, values are displayed using the last settings.

To change port value display properties

1. Do one of the following:

   • Click the V icon on the connection.

   • Right-click over a displayed port or connection and choose Show Values Properties.

2. Specify the desired display options and click OK. See AttributeDisplay Property Editor [Properties Reference].

To hide values for a port

Do one of the following:

• Middle-click on a connection whose port values are currently displayed.

• Right-click over a connection or input port and choose Hide Values.

The display settings are remembered and reused the next time you display values on that port.

To hide all values in the current view

To hide all values shown for the current tree, or the current compound and its sub-compounds, do one of the following:

• Choose Show Hide All Port Values.
• Right-click in the background of the ICE tree view, and choose Hide All Port Values.

To hide all values for the selected compounds

To hide all values shown for the selected compounds:

• Choose Show Hide Port Values for Selected Node(s).
• Right-click in the background of the ICE tree view, and choose Hide Port Values for Selected Node(s).

To hide or unhide all port value displays in a specific view

Do one of the following:

• Click the eye icon (Show menu) in a view's toolbar and toggle Display/ICE Attributes.

  or

• Click the eye icon (Show menu) and choose Visibility Options. On the Attributes tab, toggle Display/ICE Attributes. You can set this option separately for selected and unselected objects.

Note that this affects both AttributeDisplay properties on objects as well as port value displays in ICE trees.

To hide or unhide all port value displays in all views

• Choose Display Visibility Options (All Cameras). On the Attributes tab, toggle Display/ICE Attributes. You can set this option separately for selected and unselected objects.

Note that this affects both AttributeDisplay properties on objects as well as port value displays in ICE trees.

To log port values

1. Connect a Log Values nodes from the Debug category of the Tools tab of the preset manager between two ports in the tree. Both the In and Out ports of the Log Value node must be connected.

2. If desired, set or connect the Log Value node's other ports and parameters. See Log Values [ICE Reference].

3. Force the tree to recalculate somehow, for example, by advancing one frame on the timeline.

To profile the performance of ICE trees

1. Start the performance timers.

   This setting is per tree, so you should start the performance timers on all trees that you want to profile.

2. Play back the scene, or advance some frames.

3. Display performance highlights: Time (Top Thread) or Time (All Threads).

   You can stop the timers or leave them running as desired.

   See Interpreting Timer Data for information about what the numbers mean.

4. If required, make some changes to the ICE tree and profile it again.

   If you don't want to accumulate timing data, make sure to reset the timers first.

Interpreting Timer Data

When you display performance highlights, the numbers on each node indicate how long that node took to execute, and the numbers on the connections indicate the how long that branch took to execute (that is, the time taken by all nodes upstream). These values are meant as rough guides and won't add up exactly because of various overheads.

The nodes and connections that took the longest to execute are highlighted in yellow, orange, or red depending on what percentage of the total time of the tree or compound that they took. Note that Execute nodes and connections do not always show execution times because of how they work internally.

• For Time (All Threads), the numbers show the total time taken by all threads. The number on the root node shows the time taken for the evaluation of the entire tree.

• For Time (Top Thread), the numbers show the time taken by the longest thread for each node and connection. In this mode, the numbers do not add up because different threads may take the longest amount of time in different nodes on the same branch. The number on the root node shows the total time taken for the evaluation of the entire tree plus any inputs that were called and evaluated — for example, if the tree gets the point positions of an object, the time taken to evaluate any deformations is included.

When analyzing these numbers, here are some things to keep in mind:

• If the value shown by Time (Top Thread) is high but still close to the average, that is, close to the value shown by Time (All Threads) divided by the number of threads on your computer, then all you can conclude is that a node did a lot of computing. There may be very little you can do to optimize it further, except to avoid computationally expensive nodes — for example, use Squared Length instead of Length when comparing vectors, or do some checking to avoid calculations unless necessary.

• If the value shown by Time (Top Thread) is much larger than the average, then it represents a bottleneck or a critical path in the tree. Depending on your tree, you may be able to rearrange the nodes and branches to minimize the impact of bottlenecks.

• If the times shown by Time (Top Thread) and Time (All Threads) are identical, then the node was not multithreaded at all. This may be because a custom node does not support multithreading, but it is also normal when dealing with a small amount of data. Multithreading imposes an overhead, and ICE does not multithread if it's not worth doing.

• It's normal to have small numbers on nodes that were not executed at all (for example, because of an If node). This time represents initialization and pre-evaluation.

• When there are multiple connections from an output port, it's normal that most of the evaluation time is shown on the first connection that gets pulled. The other connections typically show the time taken to retrieve the cached values. However, if two or more output connections from the same port show high values, then you should consider storing and retrieving the data as a custom attribute.

• If there are multiple connections between a pair of nodes, then the same time is shown on all connections. This is the total time taken by all the connections between the nodes, not the time taken by each one individually. Make sure not to count this value twice when comparing branch times.

• It can sometimes appear as though a node turns back the clock and the time taken by its input connections is greater than the time taken by the output connection that pulls the node first. This is an illusion caused by multiple output connections — some of the time taken by the input connections is counted against the other output connections. The total time taken by all the inputs plus the node itself is roughly equal to the total time taken by all the outputs.

• Sometimes the time shown on a compound and the time shown on its output connection are different. This is likely due to various overheads.