Improved zoom and navigation performance for large graphs with many nodes

[dimven-adsk]

Purpose

Currently large graphs perform very poorly. It can take up to multiple seconds to zoom in and out, particularly when moving past the 0.4 zoom stage, where the node and port names disappear and the effect borders appear. Panning the view can also be slow.

There are multiple reasons for this slowdown but the biggest contributor by far are the many fade in/out animations that happen at that particular transition. This was particularly difficult to trace, because the slowdown does not happen in the C# managed code. Instead, it actually comes from the multiple animation bindings to the "Zoom" property of the WorkspaceViewModel in every single node. This is why the hotpath stops at raising the property changed event and can not be expanded further:

From what I've gathered, WPF animations get pre-compiled to native platform code and that is why we can't get further details in both VS and dotTrace.

This is further exasperated by the fact that the animations target the contols' opacity property. Apparently when you modify an element’s opacity property, it can cause WPF to create temporary surfaces which results in an even bigger performance hit.

With this PR, I propose we have a cut-off point after a certain number of nodes are placed, where the animations are turned off (for example after placing 150 nodes on the canvas).

Another reason highlighted in the above image, is that every single placed node and group throws a binding failure, which slows down graph loading/rendering times. In the PR I propose that we simplify the XAML visual tree, which avoids the binding failures and is beneficial to the overall performance. Plus, since the node icons are already so tiny, we can further improve the performance of large graphs by using speedier image rendering options.

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User Experience

Currently with a graph of around 350 nodes, each zoom in/out action can take multiple seconds, which totally breaks the flow:

With the proposed changes, animations still work for small graphs but for large graphs they are replaced with data trigger setters that replicate the end state:

TODO: This is based on our scope from last quarter and was targeting an older release of Dynamo (distributed with the latest version of Revit at that time). There are some merge conflicts to clear.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

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[pinzart90]

I don't know how important the Animations are for UX, if they are required, another option would be to try to apply them for fewer UI elements (like the main node grid). It does seem like, at least. the fade animations are applied to all border types, some to FrameworkElement and others to TextBlocks

[dimven]

Hi @pinzart90, I merged the updates from the main branch and resolved the merge conflicts

[mjkkirschner]

it's really hard to review this with all of these formatting changes, can you revert them and keep just the significant changes?

[dimven-adsk]

I don't think that's possible. The changes were from a few months ago. I rebased from main and that pulled hundreds of commits. I think I'll have to make a new branch and a new PR. I'll be sure to remember to turn off code cleanup next time.

[mjkkirschner]

Thanks @dimven-adsk - let’s create a new pr and close this one.

[dimven-adsk]

Closing this one and continuing it here