three.js Example

• Use Case:
  • Google Street View
• Equirectangular Projection（等距圓柱投影）

• Paste this image on a sphere.
• Saw this kind of image before?

• Problems:
  • ProblemsMobile device not support WebGL
  • Android 4.1 native supports this format
  • Want to build a web service to serve this image format and support mobile device

• How about
  • Use hyperrectangular instead of sphere Which is much simpler
  • Cubic Projection !!

Demo: CSS cubic

• Images!!

• How to get the image for six faces?
• Ref: Converting an Equirectangular Panorama to Cubic Faces
  • CPAN Panotools for erect2cubic
  • Hugin for nona
  • /Applications/Hugin/HuginTools/nona
  • See Here

• θ is ?

  theta = Math.atan2(0.5l, d);

Demo: CSS #1

• Somthing still wrong
• How about increase the face of the polygon

• Hard to generate images for dodecahedron
  • Use google stree view image API
  • Not perfect

Demo: CSS dodecahedron

• Learned:

  • Use SVG clippath to clip the pentagon（五邊形） or you will see face overlape
  • Remember to center pentagon, it is smaller than the square.

• Problems

  • Must support SVG
  • Must work well when use both SVG and 3D transform

• Actually…
• My perspective is wrong on cubic version
• Thanks bigcat

Demo: CSS

• Problem:
  • Canvas support is better than 3D transform (ref: caniuse)

• three.js supports 2d canvas….
• Other 3D library also supports too.

Demo: three.js 2D example, please open in Firefox.

• Implement 3d projection by 3D JS library