Added alpha texture support #124
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| writeChannel(pixels, blueChannel, 2); | ||
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| // First try reading the alpha component from the alpha channel, but if it is a single color read from the red channel instead. | ||
| var alphaChannel = getTextureChannel(alphaTexture, 3, width, height, scratchChannel); |
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I think it would be better if this line was in in the else part. The cost here is reading the entire channel twice vs using an else and in this case, the else would be better.
Alternately, you can have a shortcut exit from the getTextureChannel function that returns if the channel number is beyond the number of channels available.
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Reading the alpha channel before the red channel is probably safer. There could be a case where someone sets the diffuse slot and alpha slot to the same texture, in which case getting the transparency from the red channel would be a mistake.
| var greenChannel = getTextureChannel(diffuseTexture, 1, width, height, scratchChannel); | ||
| writeChannel(pixels, greenChannel, 1); | ||
| var blueChannel = getTextureChannel(diffuseTexture, 2, width, height, scratchChannel); | ||
| writeChannel(pixels, blueChannel, 2); |
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How about adding a function that writes RGB at once? That way you can read the channels and then just use a single writeChannels function.
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I believe the purpose of doing it this way was so we could use the same scratchChannel and only need to read a single channel of the texture at a time.
Added support for parsing
map_din the mtl file. The alpha texture is packed with the diffuse texture.@shehzan10 - would you like to review? No rush at all with this.
Tested with red-baron.zip from https://groups.google.com/d/msg/cesium-dev/FFKF3N77FmQ/4kBkgD4qBAAJ
Command for running:
node bin/obj2gltf.js -i red-baron/red-baron.obj --metallicRoughness