New video tutorial has been uploaded. 3D stage designing with baby steps, but requires a good basic on 2D sprites and such.
The video approach is also experimental. I'm less showing "typing" (unless necessary) and skipping the things we already know. So code might suddenly pop into the video or illustrations shown briefly. The reason is that I want to make it a more 'break-down' approach instead of one huge tutorial video. This is part 1 which will introduce you to 3D drawing.
The tutorial can be found here:
https://www.youtube.com/watch?v=kEM1LUTrur4 and is called: [ 弾幕風 PH3 Tutorial ] 3D stages 【Part 1】
Next tutorial I am planning will slightly expand on this and introduce fog + "stage scrolling"
And later on a third tutorial will be made to discuss 2D and 3D camera usage.
Good luck.
EditPart 2 of the tutorial has been added.
https://www.youtube.com/watch?v=qL4XCwxioRU