Anyone working with the Forge Model Derivative service knows that SVF is meant for streaming design data for online viewing with the Forge Viewer. A new version of this format, SVF2, has been in beta for the past several months, and is getting ready for General Availability (GA) release. The Model Derivative service produces SVF2 derivatives by optimizing and sharing meshes within the same Viewable, and even across multiple Viewables when possible. Because of this optimization, the SVF2 format greatly reduces Viewable storage size and speeds up viewing and loading performance.
We received very positive feedback during the beta period and want to really thank those customers who tested and shared their experience with us. We had two major categories of feedback that were around geometry corruption, and property metadata where dbids were not matching those of the viewer. I am happy to announce both issues have been addressed and are now in the production environment. In the coming weeks, we are planning to move to a general availability (GA) release, so this is your last chance to provide any additional beta feedback. The GA release was scheduled for the week of July 12th and I am happy to report SVF2 is production ready now. As always, you can request support through the Forge help options defined here: https://forge.autodesk.com/en/support/get-help
When should you use SVF2?
For new translations SVF2 should be your primary choice now. There is really only one strong reason to choose the older SVF format: Currently SVF2 does not handle physical materials coming from 3ds Max. This is under review and will be updated soon.
Should you retranslate existing models?
If performance is a concern with your current models, then yes it may help. Larger AEC oriented models coming from Revit, or IFC formats can typically benefit from retranslation. In most cases there should be some performance improvement, but because the optimization is geometry-specific, and source formats can include their own optimization, it does not always make a significant difference.
What is the difference between SVF and SVF2?
SVF2 optimizes the geometry by using instances instead of unique geometry. As a result, there are a few things to be aware of when working with SVF2. The Model Derivative service now treats each format as a separate and mutually exclusive format. Once you translate to one of the formats, you cannot in parallel have a second translation of the same seed file as the opposite format. You can only have one at a time. This is to minimize issues with object identification. The dbids specifically will be different between the two formats. External ids of course will be the same and are not impacted. Therefore, as always, it is important to use the external ID for any external connections, for example with a database.
The SVF2 workflow is like SVF with only format and Viewer environment changes. See this post for more technical details: https://forge.autodesk.com/blog/svf2-public-beta-new-optimized-viewer-format. Please note that previous beta OTG/Fluent workflows coming from BIM 360 services are now deprecated. To use the Forge Viewer on BIM 360 URNs, simply follow the steps for viewing SVF2.
As always, it is best to use the latest Viewer version, but remember you must use at least version 7.25. New versions of the Viewer provide additional support for SVF2. See change log for details: https://forge.autodesk.com/en/docs/viewer/v7/change_history/changelog_v7/
For additional details please see the latest blog posts here: