- Implemented saturation parameter for lightmaps [#85]

[Aadjou]

Scope & Features:

• This PR implement a lightmap saturation control for the io3d-data3d aframe component

• The changes allow the user to have full control over the look of their scene

  Design:

• The shader has been rewritten to use 'saturation' as a control mechanism for color bleeding in lightmaps
• Grayscale conversion: used ITU-R `(0.2125, 0.7154, 0.0721)´ (other option would be NTSC vec3(0.299, 0.587, 0.114)
• Issue

How to use:

• Set lightMapSaturation value from 0.0 (grayscale) to 1.0 (original) to 1.0+ (oversaturated) <a-entity io3d-data3d="key:/key.gz.data3d.buffer; lightMapSaturation: 0.0"></a-entity>
• Changes do not affect users, fallback value is neutral

How to test:

• Test (with a colorful scene) if saturation works as intended
• Check if aframe sliders work as intended

Thanks

[tomas-polach]

I'm on it. Code looks good! I especially like that you are using weighted grayscale conversion instead of just using the mathematical RGB average in https://github.com/archilogic-com/3dio-js/pull/113/files#diff-4789112aae09f0bb59ea558bff779f98R168 Will give it some testing tomorrow.

[tomas-polach]

Works like a charm! :) One minor glitch: when using lightMapSaturation:0 the value automatically jumps to the default: 1.

Proposal: Using:

this.lightMapSaturation = params.lightMapSaturation  !== undefined ? params.lightMapSaturation : DEFAULT_LIGHT_MAP_SATURATION

in: https://github.com/archilogic-com/3dio-js/pull/113/files#diff-d00d2508afc2df8d84bea5785f0cffc3R26 and:

lightMapSaturation: { value: params.lightMapSaturation !== undefined ? params.lightMapSaturation : DEFAULT_LIGHT_MAP_SATURATION },

in https://github.com/archilogic-com/3dio-js/pull/113/files#diff-d00d2508afc2df8d84bea5785f0cffc3R39