Change the texture of CubeMap/IBL used in the test to the same one

[cx20]

Currently, glft-test uses different cubemap textures for each library.
Use the same texture as much as possible because it is difficult to compare.

No	Library	CubeTexture	IBL(Env map)
1	Three.js	skybox/<p|n><x|y|z>.jpg	skybox/<p|n><x|y|z>.jpg
2	Babylon.js	country.env	country.env
3	Cesium	N/A	N/A
4	ArcGISJSAPI	N/A	N/A
5	Grimore.js	N/A	N/A
6	xeogl	cloudySkyBox.jpg	N/A
7	minimal-gltf-loader	skybox/<p|n><x|y|z>.jpg	bakedDiffuse_0<1|2|3|4|5|6>.jpg
8	Khronos glTF Loader	N/A	N/A
9	ClayGL	skybox/<p|n><x|y|z>.jpg	pisa.hdr
10	Hilo3d	skybox/<p|n><x|y|z>.jpg	bakedDiffuse_0<1|2|3|4|5|6>.jpg
11	PlayCanvas	Helipad_<pos|neg><x|y|z>.png	Helipad.dds
12	X3DOM	papermillDiffuse.dds	papermillDiffuse.dds
13	CZPG.js	skybox/<p|n><x|y|z>.jpg	bakedDiffuse_0<1|2|3|4|5|6>.jpg
14	GLBoost	papermill/environment/environment*.jpg	papermill/diffuse/diffuse*.jpg
15	RedCube.js	N/A	pisa.hdr
16	RedGL	skybox/<p|n><x|y|z>.jpg	skybox/<p|n><x|y|z>.jpg
17	Ashes	N/A	helipad/<pos|neg><x|y|z>.hdr
18	Unity	skybox/<p|n><x|y|z>.jpg	N/A
19	pex	pisa.hdr	pisa.hdr
20	Filament	syferfontein_18d_clear_2k_skybox.ktx	syferfontein_18d_clear_2k_ibl.ktx

[cx20]

I chose PaperMill as the basic HDR texture for CubeMap / IBL.
http://www.hdrlabs.com/sibl/archive/downloads/PaperMill_Ruins_E.zip

I will prepare each type of texture by referring to the following information.

dds (for PlayCanvas):
https://developer.playcanvas.com/en/user-manual/assets/cubemaps/

6 jpg files (for PlayCanvas):
https://forum.playcanvas.com/t/how-to-dynamically-configure-skybox-with-javascript/12980
https://forum.playcanvas.com/t/how-do-i-apply-gamma-correct-to-cubemap-textures/14741

dds (for Babylon.js):
https://doc.babylonjs.com/how_to/use_hdr_environment

env (for Babylon.js):
https://doc.babylonjs.com/how_to/use_hdr_environment
https://forum.babylonjs.com/t/how-to-create-env-texture-file/9073

hdr (for RedCube / pex)
https://github.com/google/filament/tree/master/tools/cmgen

cmgen.exe -x . --type=equirect --format=hdr --size=512 --no-mirror papermill.hdr

ktx (for Filament):
https://github.com/google/filament/tree/master/tools/cmgen

cmgen.exe -x . --format=ktx --size=512 papermill.hdr

jpg (for xeogl):

1. hdr -> 6 png files : https://github.com/google/filament/tree/master/tools/cmgen
2. 6 png files -> dds (h-cross) : https://github.com/Microsoft/DirectXTex/wiki/Texassemble
3. dds (h-cross) -> jpg (h-cross) : https://www.getpaint.net/index.html

6 jpg/hdr files:
https://github.com/ux3d/glTF-Sample-Environments/tree/4eace30f795fa77f6e059e3b31aa640c08a82133/papermill

[Yuki Shimada]

@cx20 Not only IBL, In these CG pipelines, libraries/engines people have their own policy/thought.
So It's difficult to unify those libraries way to only one.

In my opinion, a realistic solution would be making an automation tool.
This tool gets HDR env image and calls each library's IBL pipeline script, and finally outputs pre-filtered textures for them.

[cx20]

I basically decided to use PaperMill for CubeMap / IBL in gltf-test.
However, I noticed that there were cases where the orientation of the cubemap and the orientation of the model did not match, so I decided to investigate.

Original Image:
http://www.hdrlabs.com/sibl/archive/downloads/PaperMill_Ruins_E.zip

The following are the differences in the display results for each library.

The following are the test results and comments. Please note that it may be a usage issue, not a library.

Library	BoomBox + CubeMap result	CubeMap Texture (Spector.js result)	Orientation Test result
Three.js			❌ Left and right sides of CubeMap texture are reversed
Babylon.js			❌ Different orientation
Filament			❌ Different orientation
PlayCanvas			❌ Different orientation
Rhodonite			✅ CubeMap and model orientation match
GLBoost			❌ Different orientation

[cx20]

I think the problem with cubemaps in Three.js was fixed in #424.

[cx20]

I think the problem with cubemaps in PlayCanvas was fixed in #512