Because of how ICE is optimized, it won’t bother setting data if you never use that data (see Beware of ICE Optimizations here). For example, suppose I have a point cloud where I set a per-point scalar value, but I never use that scalar data (because I just want to cache that value and use it later).
That scalar attribute is never used, so it is optimized away (it makes sense: you’re not using it, so why keep it?). You won’t see that attribute in the Cache Manager, and the Cache on File node won’t write it out (even if you add that attribute to the list).
One way to force ICE to evaluate the attribute so you can cache it is to create an Attribute Display property for the attribute, but disable Show Values.
Another way is to insert a Log Values node, and disable logging.
Yet another way is to use Show Values. Enable Show Values for Tagged Components Only to hide the values (if you’re going to tag components, you could set the Display % to 1).
And last but not least, if you have emTools from Mootzoid, you can use the Force Value Evaluation node, which uses a Show Values on a value that is never set.
hat tips to Stefano, Mathieu, and Vincent on the SItoA list
Sometimes it can be useful to turn on Use Global Coordinates for Display. Because otherwise you’re going to be looking at points in local space, and that can mess up your thinking.
Here’s a simple example to show the difference. Purple is global, light green is local. As you can see, the purple points match up with the actual coordinates.
Now here’s a better example of the usefulness of Use Global Coordinates for Display. Red is local (and misleading). Yellow is global. Imagine you’re doing all kinds of coordinate system conversions in a complicated tree, and then you decide to show values as points. If you’re not careful, like me sometimes, you end up doubting everything you’ve done and pulling it all apart.
Use the SKip Default Values During Display or Show Values Computed at Current Frame options when you do a Show Values on the output of a Filter node.
With the default Show Values settings, you’ll see default values for the elements that didn’t pass the filter condition:
If you enable SKip Default Values During Display or Show Values Computed at Current Frame , then you see values for the filtered elements only: