Hi All, In our application we add and remove a lot of nodes to the scene graph regularly, and also make use of em font sizes to scale certain parts of our application. We've noticed performance issues when adding nodes to the scene, and it seems to be related to em sizes in our css.
As a test we added a chain of 20 stackpanes to a root stackpane. On the root, we set a font size of 8pt via inline css. We then added and removed a new tableview from the deepest stackpane 500 times, waiting for the node to render after each add and remove. In each of the experiments, we compared adding tableviews without css and adding tableviews with an inline css font size of 8pt. We then tried setting different font sizes in the stackpane chain. I've attached sample code for these experiments. The results (on jdk 9.0.4 - jdk 10 was similar) are as follows: Setting a 1em font size on all stackpanes except the root. With font on tableview: 14707ms Without font on tableview: 27725ms Setting a 1em font size on the first child of the root only. With font on tableview: 14221ms Without font on tableview: 19187ms Using the original setup with no additional fonts. With font on tableview: 13990ms Without font on tableview: 13847ms It looks like using a relative font size has a large effect performance wise on descendant nodes. I would expect some amount of font size caching in the chain of stackpanes since I'm reusing the same chain and adding/removing nodes from that chain repeatedly. I'm not sure how valid my test is, or how much of an issue this really is in practice? Dean
