5.2.0: updated underlying engine (better shadow maps, float-based images for shaders), cycle viewpoints, fixed multi-viewport

We're proud to release new versions 5.2.0 of Castle Model Viewer and Castle Model Converter (the downloads below contain them both).

Highlights of this release (since 5.0.0):

• Engine upgraded to the finally released Castle Game Engine 7.0-alpha.3 version. The previous version was based on an engine effectively somewhere between 7.0-alpha.2 and 7.0-alpha.3.

• Reworked the shadow maps logic - much simpler now, using the shadows field at light node doesn't process the scene graph "under the hood" anymore. Some difficult / buggy situations are thus solved and we are ready for future shadow maps improvements.

  Out of necessity, we also had to remove (already deprecated) support for using GeneratedShadowMap node in the Appearance.texture list. This was too convoluted to support (because shadow map does not affect the shape look like other textures on Appearance.texture, the shadow map effect is applied at the specific light source query). You can now only use GeneratedShadowMap inside the defaultShadwMap field of the light node.

• Float-based images support. In case of Castle Model Viewer, this means that loading 16-bit PNG images of float-based KTX images is useful for shader effects, as shaders will get full float values from the image. This extra precision sometimes matters a lot, e.g. if you use a texture for a heightmap in the shader.

• Cycle through viewpoints when you use Page Up, Page Down or the corresponding menu items.

• Fixed display when usign multiple viewports (Display -> 2 Horizontal Viewports, Display -> 4 Viewports).