VERSION 4.0: domain rendering, backdrops and improved glass rendering

This major update brings another very flexible tool: domain rendering.
You may imagine this feature in the way, that multiple scenes are rendered at the same time, and a function (the domain-partitioning-function) specifies, where in the global space, appears which scene.
This may sound very abstract at first, but allows for some really unique effects.
For example, you may create a shape, which consists to some parts of metal, and to some parts of glass, as real 3d structure, not just a texture.
Or, you can fade in or out certain objects in a very cool way. And lots more.

Also, you can now chose images to be used as backdrop. These are integrated into the 3d space as well, so react to camera movement and also are visible in object reflections.

And, the rendering of glass is now much improved.

Complete changelog:
VERSION 4.3.2757 (17.05.2026):
- mandelbro3d:
- added option to add surfaces along domain boundaries (SWAN-1588)
- allow parenting of objects across domains (SWAN-1591)
- added support for upto 4 domains (SWAN-1594)
- improved rendering of internal structures when using glass-material (SWAN-1585)
- improved transparency rendering of transparent PBR- and glass-material (SWAN-1586)
- fixed: the timer showing render-time did not stop after finishing a render (SWAN-1589)
- fixed: adjustment of light did not show up at all in the fast preview (SWAN-1584)
- added preview-images for the domain-partitioning-functions in the item-picker (SWAN-1595)
- create missing preview-images for the deforming-variations-picker (SWAN-1237)
- motion-curves-editor: added load/save keyframes to/from *.csv-files (SWAN-837)
- created new splash screen for version 4.0 (SWAN-1592)
- updated users manual for version 4.0 (SWAN-1596)

VERSION 4.2.2745 (16.05.2026):
- mandelbro3d:
- added backdrop-image-option (SWAN-1576)
- added support for a sequence of images for the backdrop function (SWAN-1577)
- added positioning-options for the backdrop function (SWAN-1578)
- added balancing-controls for the backdrop function (SWAN-1579)
- added option to mix the backdrop with the sky (SWAN-1580)
- added tiling options for the backdrop function (SWAN-1581)
- added new folder-setting for the backdrop-folder in the application settings (SWAN-1582)
- added "Sine Wave"-domain-partitioning function (SWAN-1572)
- added "Sphere"-domain-partitioning function (SWAN-1573)
- added "Variation"-domain-partitioning function (SWAN-1574)

VERSION 4.1.2735 (15.05.2026):
- mandelbro3d:
- introduced global domain objects (which are visible in all domains) (SWAN-1564)
- implemented loading/saving scenes with domains (SWAN-1563)
- add "Pick Position"-function to pick center of a domain-partitioning function (SWAN-1565)
- add "Gyroid"-domain-partitioning function (SWAN-1568)
- add "Half-Space"-domain-partitioning function (SWAN-1569)
- add "Onion"-domain-partitioning function (SWAN-1570)
- added "Radial Pie"-domain-partitioning function (SWAN-1571)
- removed "Procedural Textures 2" and "Procedural Textures 3" example scenes completely (SWAN-1575)
- added "City-lights" procedural texture
- the shortcut for the scale-gizmo conflicts with the WSAD-camera-movement (SWAN-1583)

VERSION 4.0.2725 (14.05.2026):
- mandelbro3d:
- implemented domain-rendering in the core-renderer (SWAN-1558)
- introduced-domain-partitioning functions (SWAN-1559)
- added item-picker for domain-partitioning functions (SWAN-1560)
- added support for creating a new domain in the UI (SWAN-1561)
- implement switching between domains in the UI (SWAN-1562)
- added "Box"-domain-partitioning function (SWAN-1566)
- added "Checkerboard 3D"-domain-partitioning function (SWAN-1567)
- fixed: region rendering has stopped to work (SWAN-1557)

VERSION 3.45.2729 (12.05.2026):
- mandelbro3d:
- added text-search for the item-picker (SWAN-1170)
- fixed: Faehrten (and others) white screen (SWAN-1548)
- the Transform-tab (which is not used here) is now hidden on formulas which are inside a hybrid (SWAN-1549)
- removed Julia-slot-settings at hybrid level (individual formulas have their own Julia-settings) (SWAN-1551)
- added Bailout-option at hybrid-level (SWAN-1552)
- fixed typo at the variations browser window (SWAN-1547)
- fixed: motion curve: clear curves-cache after moving a key-frame (SWAN-1590)
- fixed: transparent background in rendering animations (SWAN-549)
- added folder for motion-curves in the application-settings (SWAN-838)
- removed the option "Batch size appl. startup" from the application-settings (SWAQN-1058)
- avoid to generate a start-flame when MandelBro3D is started as initial module (SWAN-1593)
- the application setting "random motion duration" is now respected when generating random flames (SWAN-1058)