Change History › 5.6.0
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5.6.0 Change Notes

Quantity Formatting

Ratio Format Enhancements

Ratio formats now support automatic scale factor conversion when using 2-unit composite formats. This enables proper display of architectural scales (e.g., 1/4"=1') and metric scales (e.g., 1:100) with automatic unit conversion.

How it works:

  • When a Ratio format has exactly 2 units in its composite.units array, the system automatically computes scale factor conversion
  • The first unit represents the numerator, the second represents the denominator
  • Both units must have matching phenomena (e.g., both LENGTH)
  • Scale factor is computed dynamically from the denominator→numerator conversion
  • Supports both decimal and fractional display modes

For detailed examples and documentation, see the Quantity Formatting documentation.

@itwin/presentation-common

Additions

  • Added parentArrayField and parentStructField attributes to PropertiesField class to allow easier navigation to parent fields when traversing content. The new properties, together with parent property, are mutually exclusive, i.e., only one of them can be defined at a time (a field can't be a struct member and an array item field at the same time).
  • Added getFieldByName method to ArrayPropertiesField and StructPropertiesField.
    • For array field, the method returns items field if its name matches the given name.
    • For struct field, the method returns the member field with the given name, if any.

Fixes

  • Fixed content traverser (result of createContentTraverser call) not passing parent struct / array field names as parentFieldName to IContentVisitor methods.

@itwin/core-backend

Database Optimization APIs

Three new database optimization APIs have been added to maintain optimal query performance and iModel file size.

vacuum()

Reclaims unused space and defragments the database file.

// After large deletions briefcaseDb.vacuum();

analyze()

Updates SQLite query optimizer statistics.

// After large data imports or schema changes briefcaseDb.analyze();

optimize()

Performs both vacuum() and analyze() operations in sequence. This is the recommended way to optimize an iModel.

For convenience, optimization can be performed automatically when closing an iModel by using the optimize property of the CloseIModelArgs:

// Automatically optimize when closing briefcaseDb.close({ optimize: true });

Alternatively, call optimize() explicitly for more control over when optimization is needed:

// Optimize before closing briefcaseDb.performCheckpoint(); // Changes might still be in the WAL file briefcaseDb.optimize(); briefcaseDb.saveChanges(); // Later close without re-optimizing briefcaseDb.close();

TextAnnotation render priorities

TextAnnotation elements now support custom render priorities for better control over z-ordering in 2D views. The new renderPriority option in appendTextAnnotationGeometry allows you to specify different priorities for annotation labels versus other annotation geometry (frame, leaders, etc.).

import { appendTextAnnotationGeometry } from "@itwin/core-backend"; // Set different priorities for text labels and annotation geometry appendTextAnnotationGeometry({ annotationProps, layout, textStyleResolver, scaleFactor, builder, categoryId, renderPriority: { annotationLabels: 100, // Priority for text block and fill annotation: 50, // Priority for frame, leaders, and other geometry }, });

The render priority values are added to SubCategoryAppearance.priority to determine the final display priority. This allows text annotations to render correctly relative to other 2D graphics. Note that render priorities have no effect in 3D views.

Display

BENTLEY_materials_planar_fill

Support has been added for the proposed BENTLEY_materials_planar_fill glTF extension.

This allows iTwin.js to process and apply the above extension when loading glTF files. This means mesh primitives will be able to have planar fill display properties specified and respected in iTwin.js when loaded via glTF. The extension supports controlling whether meshes are filled in wireframe mode, whether they fill with the background color, and whether they render behind other coplanar geometry belonging to the same logical object.

When this extension is present on a material, iTwin.js will apply the appropriate fill flags to control the rendering appearance of the associated mesh geometry.

Here is an example of wireframeFill being applied to a test dataset:

A rendering pointing to three colored quads with varying wireframeFill properties as specified via BENTLEY_materials_planar_fill

Here is an example of backgroundFill being applied to a test dataset:

A rendering pointing to one colored quad indicating its backgroundFill property is respected as specified via BENTLEY_materials_planar_fill

Here is an example of behind being applied to a test dataset:

A rendering pointing to an overlapping pair of colored coplanar quads indicating the behind property is respected as specified via BENTLEY_materials_planar_fill

EXT_textureInfo_constant_lod

Support was added for the proposed EXT_textureInfo_constant_lod glTF extension which supports constant level-of-detail texture mapping mode for glTF models. The mode is already supported for iModels, see the documentation from when it was introduced for more information.

iTwin.js supports EXT_textureInfo_constant_lod on the baseColorTexture property in glTF model materials, with fallback to emissiveTexture if baseColorTexture is not present. When the extension is present on normalTexture, it is only applied when baseColorTexture (or emissiveTexture) also has the extension, and the constant LOD properties from the base texture are used for both to keep texture mapping in sync.

The extension is not supported for occlusionTexture and metallicRoughnessTexture.

Last Updated: 05 February, 2026