Plugins + Scripts PictureToSkybox

What’s new:

1. 6-face skies work now. Cross or strip maps: set Mapping to 6 Frames. No convert-to-panorama step.

2. 180 and 3D layout show on desktop too. You don’t have to jump into VR just to set them.

3. You can pull highlights into the reflection. Threshold / Smoothness — crank them if you only want the sun and lights in the bounce.

4. Default IBL is stronger. At exposure 1 the environment actually shows up. specIntensityMul starts at 0.25.

5. Cubemap size: 256 / 512 / 1024, default 512. Drop it on a weak machine, push it when you want cleaner reflections.

6. Refresh mode: live, after you stop dragging, or manual. Sliders won’t rebake every frame.

7. Presets. Texture, shape, exposure, all of it — save and load later.

1. Optimization: a problem that may not work when adjusting "specIntensityMul".
2. "3D Layout" and "Type" are only displayed in VR mode to avoid misleading. These two options are only effective in VR mode.
3. When in 3d layout, fix the correctness of environmental reflection.
4. Provide 3d layout a sample picture（capture from The Witcher 3）.

This update adds a core function: the skybox generated by the picture supports the native environmental reflection.
The following is a demonstration video.

1. Add support for hemispheres. In this way, you can reduce the package size by half without reducing the quality of the sky ball.

2. Additional parameters have been added.