Max GLTFExporter: Material exportation very slow with large bitmaps.

[Selmar]

Exporting materials is abnormally slow. it is stuck exporting gltf materials for a long time. The total export time is 144 seconds. I don't recall it being this slow last month (same file).

Initially I thought the problem was because I had very large textures attached (multilayer .tiff, > 100 MB), however after replacing the maps with previously exported .jpg files, it still takes around 140+ seconds.

If copy textures to output is selected, the time increases to around 240 seconds (I did not test this with the smaller textures).

There is nothing abnormal about the exported materials.

	"materials": [{
			"pbrMetallicRoughness": {
				"baseColorFactor": [0.612745166, 0.612745166, 0.612745166, 1.0],
				"metallicFactor": 0.0,
				"roughnessFactor": 0.9
			},
			"emissiveFactor": [0.0, 0.0, 0.0],
			"name": "04 - Default"
		}, {
			"pbrMetallicRoughness": {
				"baseColorFactor": [1.0, 1.0, 1.0, 1.0],
				"baseColorTexture": {
					"index": 0
				},
				"metallicFactor": 0.0,
				"roughnessFactor": 0.9
			},
			"emissiveFactor": [0.0, 0.0, 0.0],
			"name": "09 - Default"
		}, {
			"pbrMetallicRoughness": {
				"baseColorFactor": [1.0, 1.0, 1.0, 1.0],
				"baseColorTexture": {
					"index": 1
				},
				"metallicFactor": 0.0,
				"roughnessFactor": 0.9
			},
			"emissiveFactor": [0.0, 0.0, 0.0],
			"name": "05 - Default"
		}
	],

[noalak]

Export duration has been drastically reduced when 'Copy textures to output' feature is disabled.

When exporting materials, images are read, each pixel is processed and resulting image is written. We are aware it's a long process, even more for larger images. But there is nothing we could do.

An example is the combinaison of metallic and roughness maps into a single map when exporting a Physical material. More details here.