HDR/EXR texture loader examples: replaced images; added attribution

[WestLangley]

No description provided.

[looeee]

It would be good to have a smaller step size on the exposure, or even a logarithmic slider. You can really see the variation in brightness in the 0.001 to 0.1 range but you can't select that with the slider currently.

[mrdoob]

Thanks!

[WestLangley]

@mrdoob I now recommend removing the webgl_hdr.html example. We do not require custom shaders to decode HDR files. How do you feel about that?

[WestLangley]

Actually, we could add webgl_loader_texture_rgbm.html if you want...

new THREE.TextureLoader().load( 'textures/cube/pisaRGBM16/nz.png', function ( texture ) {

texture.encoding = THREE.RGBM16Encoding;

[mrdoob]

Yes and yes! 😁