Merge pull request #67 from ux3d/fix/OMI_audio_emitter

Suggestion for fixes and improvements

extensions/2.0/OMI_audio_emitter/README.md

@@ -7,6 +7,7 @@
 * K. S. Ernest (iFire) Lee, Individual Contributor
 * Michael Nisbet, Individual Contributor
 * humbletim, Individual Contributor
+* Norbert Nopper, UX3D [@UX3DGpuSoftware](https://twitter.com/UX3DGpuSoftware)
 
 ## Status
 
@@ -43,7 +44,7 @@ Audio emitter objects may be added to 3D nodes for positional audio or to the sc
         {
           "name": "environment emitter",
           "type": "global",
-          "gain": 1,
+          "gain": 1.0,
           "loop": true,
           "playing": true,
           "source": 0
@@ -57,10 +58,10 @@ Audio emitter objects may be added to 3D nodes for positional audio or to the sc
           "source": 1,
           "coneInnerAngle": 6.283185307179586,
           "coneOuterAngle": 6.283185307179586,
-          "coneOuterGain": 0,
+          "coneOuterGain": 0.0,
           "distanceModel": "inverse",
-          "maxDistance": 10,
-          "refDistance": 1,
+          "maxDistance": 10.0,
+          "refDistance": 1.0,
           "rolloffFactor": 0.8
         }
       ]
@@ -79,7 +80,7 @@ Audio emitter objects may be added to 3D nodes for positional audio or to the sc
   "nodes": [
     {
       "name": "Duck",
-      "translation": [1, 2, 3],
+      "translation": [1.0, 2.0, 3.0],
       "extensions": {
         "OMI_audio_emitter": {
           "audioEmitter": 1
@@ -128,11 +129,11 @@ When storing audio data in a buffer view, the `mimeType` field must be specified
 
 #### `bufferView`
 
-The index of the bufferView that contains the audio data. Use this instead of the image's uri property.
+The index of the bufferView that contains the audio data. Use this instead of the audio source's uri property.
 
 #### `mimeType`
 
-The audio's MIME type. Required if `bufferView` is defined. Unless specified by another extension, the only supported mimeType is audio/mpeg.
+The audio's MIME type. Required if `bufferView` is defined. Unless specified by another extension, the only supported mimeType is `audio/mpeg`.
 
 #### `uri`
 
@@ -150,7 +151,7 @@ The MPEG3 Audio Format is commonly available and freely licensed.
 
 Specifies the audio emitter type.
 
-- `positional` Positional audio emitters
+- `positional` Positional audio emitters. Using sound cones, the orientation is `+Z` having the same front side for a [glTF asset](https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#coordinate-system-and-units). 
 - `global ` Global audio emitters are not affected by the position of audio listeners. `coneInnerAngle`, `coneOuterAngle`, `coneOuterGain`, `distanceModel`, `maxDistance`, `refDistance`, and `rolloffFactor` should all be ignored when set.
 
 #### `gain`
@@ -186,11 +187,11 @@ The gain of the audio emitter set when outside the cone defined by the `coneOute
 Specifies the distance model for the audio emitter.
 
 - `linear` A linear distance model calculating the gain induced by the distance according to: 
-    `1 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)`
+    `1.0 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)`
 - `inverse ` (default) An inverse distance model calculating the gain induced by the distance according to:
     `refDistance / (refDistance + rolloffFactor * (Math.max(distance, refDistance) - refDistance))`
 - `exponential` An exponential distance model calculating the gain induced by the distance according to:
-    `pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor)`
+    `pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor))`
 
 #### `maxDistance`
 
@@ -241,16 +242,16 @@ Audio emitters of type `positional` may be added to nodes using the following sy
 Note that multiple global audio emitters are allowed on the scene, but only a single audio emitter may be added to a node.
 
 ### Audio Rolloff Formula
-The Audio Rolloff range is (0, +∞). The default is 1.
+The Audio Rolloff range is `(0.0, +∞)`. The default is `1.0`.
 
 The rolloff formula is dependant on the distance model defined. The available distance models are `linear`, `inverse`, and `exponential`.
 
-- linear formula: `1 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)`
+- linear formula: `1.0 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)`
 - inverse formula: `refDistance / (refDistance + rolloffFactor * (Math.max(distance, refDistance) - refDistance))`
-- exponential formula: `pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor)`
+- exponential formula: `pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor))`
 
 ### Audio Gain Units
-The gain unit range is (0,+∞). The default is 1.
+The gain unit range is `(0.0, +∞)`. The default is `1.0`.
 - gain formula: `originalVolume * gain`
 
 ### Audio Cone Vizualized
@@ -274,6 +275,7 @@ Radians are used for rotations matching glTF2.
 
 * Third Room - https://github.com/thirdroom/thirdroom
 * Three Object Viewer (WordPress Plugin) - https://wordpress.org/plugins/three-object-viewer/
+* UX3D Experimental C++ implementation - https://github.com/ux3d/OMI
 
 ## Resources
 

extensions/2.0/OMI_audio_emitter/schema/audioEmitter.schema.json

@@ -25,8 +25,8 @@
       "gain": {
         "description": "Unitless multiplier against original source volume for determining emitter loudness.",
         "type": "number",
-        "minimum": 0,
-        "default": 1
+        "minimum": 0.0,
+        "default": 1.0
       },
       "loop": {
         "description": "Whether or not to loop the specified audio clip when finished.",
@@ -49,61 +49,61 @@
       "coneInnerAngle": {
         "description": "The angle, in radians, of a cone inside of which there will be no volume reduction.",
         "type": "number",
-        "minimum": 0,
+        "minimum": 0.0,
         "maximum": 6.283185307179586,
         "default": 6.283185307179586
       },
       "coneOuterAngle": {
         "description": "The angle, in radians, of a cone outside of which the volume will be reduced to a constant value of`coneOuterGain`.",
         "type": "number",
-        "minimum": 0,
+        "minimum": 0.0,
         "maximum": 6.283185307179586,
         "default": 6.283185307179586
       },
       "coneOuterGain": {
         "description": "The gain of the audio emitter set when outside the cone defined by the `coneOuterAngle` property. It is a linear value (not dB).",
         "type": "number",
-        "minimum": 0,
-        "maximum": 1,
-        "default": 0
+        "minimum": 0.0,
+        "maximum": 1.0,
+        "default": 0.0
       },
       "distanceModel": {
           "type": "string",
           "description": "Specifies the distance model for the audio emitter.",
           "anyOf": [
               {
                   "enum": [ "linear" ],
-                  "description": "A linear distance model calculating the gain induced by the distance according to: 1 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)"
+                  "description": "A linear distance model calculating the gain induced by the distance according to: 1.0 - rolloffFactor * (distance - refDistance) / (maxDistance - refDistance)"
               },
               {
                   "enum": [ "inverse" ],
                   "description": "An inverse distance model calculating the gain induced by the distance according to: refDistance / (refDistance + rolloffFactor * (Math.max(distance, refDistance) - refDistance))"
               },
               {
                 "enum": [ "exponential" ],
-                "description": "An exponential distance model calculating the gain induced by the distance according to: pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor)"
+                "description": "An exponential distance model calculating the gain induced by the distance according to: pow((Math.max(distance, refDistance) / refDistance, -rolloffFactor))"
               }
           ],
           "default": "inverse"
       },
       "maxDistance": {
         "description": "The maximum distance between the emitter and listener, after which the volume will not be reduced any further. `maximumDistance` may only be applied when the distanceModel is set to linear. Otherwise, it should be ignored.",
         "type": "number",
-        "minimum": 0,
+        "minimum": 0.0,
         "exclusiveMinimum": true,
-        "default": 10000
+        "default": 10000.0
       },
       "refDistance": {
         "description": "A reference distance for reducing volume as the emitter moves further from the listener. For distances less than this, the volume is not reduced.",
         "type": "number",
-        "minimum": 0,
-        "default": 1
+        "minimum": 0.0,
+        "default": 1.0
       },
       "rolloffFactor": {
         "type": "number",
         "description": "Describes how quickly the volume is reduced as the emitter moves away from listener. When distanceModel is set to linear, the maximum value is 1 otherwise there is no upper limit.",
-        "minimum": 0,
-        "default": 1
+        "minimum": 0.0,
+        "default": 1.0
       },
       "name": { },
       "extensions": { },

extensions/2.0/OMI_audio_emitter/schema/audioSource.schema.json

@@ -14,7 +14,7 @@
       },
       "mimeType": {
           "type": "string",
-          "description": "The audio's MIME type. Required if `bufferView` is defined. Unless specified by another extension, the only supported mimeType is audio/mpeg.",
+          "description": "The audio's MIME type. Required if `bufferView` is defined. Unless specified by another extension, the only supported mimeType is `audio/mpeg`.",
           "anyOf": [
                 {
                     "enum": [ "audio/mpeg" ]
@@ -26,7 +26,7 @@
       },
       "bufferView": {
           "allOf": [ { "$ref": "glTFid.schema.json" } ],
-          "description": "The index of the bufferView that contains the audio data. Use this instead of the image's uri property."
+          "description": "The index of the bufferView that contains the audio data. Use this instead of the audio source's uri property."
       },
       "name": { },
       "extensions": { },