ARCore Android SDK v1.31.0

Author: jeremyvc

LICENSE

@@ -11,8 +11,8 @@ releases](https://github.com/google-ar/arcore-android-sdk/releases)
 
 are licensed as follows:
 
-Covered by the **Google APIs Terms of Service** at
-[https://developers.google.com/terms/](https://developers.google.com/terms/)
+Governed by the **ARCore Additional Terms of Service** at
+[https://developers.google.com/ar/develop/terms](https://developers.google.com/ar/develop/terms)
 
 ===============================================================================
 Section 2: ARCore SDK source files

README.md

@@ -46,8 +46,8 @@ The SDK release notes are available on the
 ## Terms & Conditions
 
 By downloading the ARCore SDK for Android, you agree that the
-[Google APIs Terms of Service](//developers.google.com/terms/) governs your use
-thereof.
+[**ARCore Additional Terms of Service**](https://developers.google.com/ar/develop/terms)
+governs your use thereof.
 
 
 ## User privacy requirements

libraries/include/arcore_c_api.h

@@ -26,7 +26,7 @@ android {
 
 dependencies {
     // ARCore (Google Play Services for AR) library.
-    implementation 'com.google.ar:core:1.30.0'
+    implementation 'com.google.ar:core:1.31.0'
 
     // Obj - a simple Wavefront OBJ file loader
     // https://github.com/javagl/Obj

samples/augmented_faces_java/app/build.gradle

@@ -17,10 +17,12 @@
 precision mediump float;
 
 uniform sampler2D u_DepthTexture;
+uniform sampler2D u_ColorMap;
 
 varying vec2 v_TexCoord;
 
-const highp float kMaxDepth = 8000.0; // In millimeters.
+const float kMidDepthMeters = 8.0;
+const float kMaxDepthMeters = 30.0;
 
 float DepthGetMillimeters(in sampler2D depth_texture, in vec2 depth_uv) {
   // Depth is packed into the red and green components of its texture.
@@ -29,37 +31,39 @@ float DepthGetMillimeters(in sampler2D depth_texture, in vec2 depth_uv) {
   return dot(packedDepthAndVisibility.xy, vec2(255.0, 256.0 * 255.0));
 }
 
-// Returns a color corresponding to the depth passed in. Colors range from red
-// to green to blue, where red is closest and blue is farthest.
-//
-// Uses Turbo color mapping:
-// https://ai.googleblog.com/2019/08/turbo-improved-rainbow-colormap-for.html
-vec3 DepthGetColorVisualization(in float x) {
-  const vec4 kRedVec4 = vec4(0.55305649, 3.00913185, -5.46192616, -11.11819092);
-  const vec4 kGreenVec4 = vec4(0.16207513, 0.17712472, 15.24091500, -36.50657960);
-  const vec4 kBlueVec4 = vec4(-0.05195877, 5.18000081, -30.94853351, 81.96403246);
-  const vec2 kRedVec2 = vec2(27.81927491, -14.87899417);
-  const vec2 kGreenVec2 = vec2(25.95549545, -5.02738237);
-  const vec2 kBlueVec2 = vec2(-86.53476570, 30.23299484);
-  const float kInvalidDepthThreshold = 0.01;
-
-  // Adjusts color space via 6 degree poly interpolation to avoid pure red.
-  x = clamp(x * 0.9 + 0.03, 0.0, 1.0);
-  vec4 v4 = vec4(1.0, x, x * x, x * x * x);
-  vec2 v2 = v4.zw * v4.z;
-  vec3 polynomial_color = vec3(
-    dot(v4, kRedVec4) + dot(v2, kRedVec2),
-    dot(v4, kGreenVec4) + dot(v2, kGreenVec2),
-    dot(v4, kBlueVec4) + dot(v2, kBlueVec2)
-  );
+// Returns linear interpolation position of value between min and max bounds.
+// E.g. InverseLerp(1100, 1000, 2000) returns 0.1.
+float InverseLerp(float value, float min_bound, float max_bound) {
+  return clamp((value - min_bound) / (max_bound - min_bound), 0.0, 1.0);
+}
 
-  return step(kInvalidDepthThreshold, x) * polynomial_color;
+// Returns a color corresponding to the depth passed in.
+// The input x is normalized in range 0 to 1.
+vec3 DepthGetColorVisualization(in float x) {
+  return texture2D(u_ColorMap, vec2(x, 0.5)).rgb;
 }
 
 void main() {
-  highp float normalized_depth =
-      clamp(DepthGetMillimeters(u_DepthTexture, v_TexCoord.xy) / kMaxDepth,
-            0.0, 1.0);
+  // Interpolating in units of meters is more stable, due to limited floating
+  // point precision on GPU.
+  float depth_mm = DepthGetMillimeters(u_DepthTexture, v_TexCoord.xy);
+  float depth_meters = depth_mm * 0.001;
+
+  // Selects the portion of the color palette to use.
+  float normalized_depth = 0.0;
+  if (depth_meters < kMidDepthMeters) {
+    // Short-range depth (0m to 8m) maps to first half of the color palette.
+    normalized_depth = InverseLerp(depth_meters, 0.0, kMidDepthMeters) * 0.5;
+  } else {
+    // Long-range depth (8m to 30m) maps to second half of the color palette.
+    normalized_depth =
+        InverseLerp(depth_meters, kMidDepthMeters, kMaxDepthMeters) * 0.5 + 0.5;
+  }
+
+  // Converts depth to color by with the selected value in the color map.
   vec4 depth_color = vec4(DepthGetColorVisualization(normalized_depth), 1.0);
+
+  // Invalid depth (pixels with value 0) mapped to black.
+  depth_color.rgb *= sign(depth_meters);
   gl_FragColor = depth_color;
 }

samples/augmented_faces_java/app/src/main/assets/models/depth_color_palette.png

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.ar.core.examples.java.common.helpers;
+
+import android.Manifest;
+import android.app.Activity;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.provider.Settings;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
+/** Helper to ask location permission. */
+public final class LocationPermissionHelper {
+  private static final int LOCATION_PERMISSION_CODE = 1;
+  private static final String LOCATION_PERMISSION = Manifest.permission.ACCESS_FINE_LOCATION;
+
+  /** Check to see we have the necessary permissions for this app. */
+  public static boolean hasFineLocationPermission(Activity activity) {
+    return ContextCompat.checkSelfPermission(activity, LOCATION_PERMISSION)
+        == PackageManager.PERMISSION_GRANTED;
+  }
+
+  /** Check to see we have the necessary permissions for this app, and ask for them if we don't. */
+  public static void requestFineLocationPermission(Activity activity) {
+    ActivityCompat.requestPermissions(
+        activity, new String[] {LOCATION_PERMISSION}, LOCATION_PERMISSION_CODE);
+  }
+
+  /** Check to see if the array of given permissions contain the location permission. */
+  public static boolean hasFineLocationPermissionsResponseInResult(String[] permissions) {
+    for (String permission : permissions) {
+      if (LOCATION_PERMISSION.equals(permission)) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  /** Check to see if we need to show the rationale for this permission. */
+  public static boolean shouldShowRequestPermissionRationale(Activity activity) {
+    return ActivityCompat.shouldShowRequestPermissionRationale(activity, LOCATION_PERMISSION);
+  }
+
+  /** Launch Application Setting to grant permission. */
+  public static void launchPermissionSettings(Activity activity) {
+    Intent intent = new Intent();
+    intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
+    intent.setData(Uri.fromParts("package", activity.getPackageName(), null));
+    activity.startActivity(intent);
+  }
+}

samples/augmented_faces_java/app/src/main/assets/shaders/background_show_depth_color_visualization.frag

@@ -53,8 +53,8 @@ android {
 
 dependencies {
     // ARCore (Google Play Services for AR) library.
-    implementation 'com.google.ar:core:1.30.0'
-    natives 'com.google.ar:core:1.30.0'
+    implementation 'com.google.ar:core:1.31.0'
+    natives 'com.google.ar:core:1.31.0'
 
     implementation 'androidx.appcompat:appcompat:1.1.0'
     implementation 'com.google.android.material:material:1.1.0'

samples/augmented_faces_java/app/src/main/java/com/google/ar/core/examples/java/common/helpers/LocationPermissionHelper.java

@@ -17,10 +17,12 @@
 precision mediump float;
 
 uniform sampler2D u_DepthTexture;
+uniform sampler2D u_ColorMap;
 
 varying vec2 v_TexCoord;
 
-const highp float kMaxDepth = 8000.0; // In millimeters.
+const float kMidDepthMeters = 8.0;
+const float kMaxDepthMeters = 30.0;
 
 float DepthGetMillimeters(in sampler2D depth_texture, in vec2 depth_uv) {
   // Depth is packed into the red and green components of its texture.
@@ -29,37 +31,39 @@ float DepthGetMillimeters(in sampler2D depth_texture, in vec2 depth_uv) {
   return dot(packedDepthAndVisibility.xy, vec2(255.0, 256.0 * 255.0));
 }
 
-// Returns a color corresponding to the depth passed in. Colors range from red
-// to green to blue, where red is closest and blue is farthest.
-//
-// Uses Turbo color mapping:
-// https://ai.googleblog.com/2019/08/turbo-improved-rainbow-colormap-for.html
-vec3 DepthGetColorVisualization(in float x) {
-  const vec4 kRedVec4 = vec4(0.55305649, 3.00913185, -5.46192616, -11.11819092);
-  const vec4 kGreenVec4 = vec4(0.16207513, 0.17712472, 15.24091500, -36.50657960);
-  const vec4 kBlueVec4 = vec4(-0.05195877, 5.18000081, -30.94853351, 81.96403246);
-  const vec2 kRedVec2 = vec2(27.81927491, -14.87899417);
-  const vec2 kGreenVec2 = vec2(25.95549545, -5.02738237);
-  const vec2 kBlueVec2 = vec2(-86.53476570, 30.23299484);
-  const float kInvalidDepthThreshold = 0.01;
-
-  // Adjusts color space via 6 degree poly interpolation to avoid pure red.
-  x = clamp(x * 0.9 + 0.03, 0.0, 1.0);
-  vec4 v4 = vec4(1.0, x, x * x, x * x * x);
-  vec2 v2 = v4.zw * v4.z;
-  vec3 polynomial_color = vec3(
-    dot(v4, kRedVec4) + dot(v2, kRedVec2),
-    dot(v4, kGreenVec4) + dot(v2, kGreenVec2),
-    dot(v4, kBlueVec4) + dot(v2, kBlueVec2)
-  );
+// Returns linear interpolation position of value between min and max bounds.
+// E.g. InverseLerp(1100, 1000, 2000) returns 0.1.
+float InverseLerp(float value, float min_bound, float max_bound) {
+  return clamp((value - min_bound) / (max_bound - min_bound), 0.0, 1.0);
+}
 
-  return step(kInvalidDepthThreshold, x) * polynomial_color;
+// Returns a color corresponding to the depth passed in.
+// The input x is normalized in range 0 to 1.
+vec3 DepthGetColorVisualization(in float x) {
+  return texture2D(u_ColorMap, vec2(x, 0.5)).rgb;
 }
 
 void main() {
-  highp float normalized_depth =
-      clamp(DepthGetMillimeters(u_DepthTexture, v_TexCoord.xy) / kMaxDepth,
-            0.0, 1.0);
+  // Interpolating in units of meters is more stable, due to limited floating
+  // point precision on GPU.
+  float depth_mm = DepthGetMillimeters(u_DepthTexture, v_TexCoord.xy);
+  float depth_meters = depth_mm * 0.001;
+
+  // Selects the portion of the color palette to use.
+  float normalized_depth = 0.0;
+  if (depth_meters < kMidDepthMeters) {
+    // Short-range depth (0m to 8m) maps to first half of the color palette.
+    normalized_depth = InverseLerp(depth_meters, 0.0, kMidDepthMeters) * 0.5;
+  } else {
+    // Long-range depth (8m to 30m) maps to second half of the color palette.
+    normalized_depth =
+        InverseLerp(depth_meters, kMidDepthMeters, kMaxDepthMeters) * 0.5 + 0.5;
+  }
+
+  // Converts depth to color by with the selected value in the color map.
   vec4 depth_color = vec4(DepthGetColorVisualization(normalized_depth), 1.0);
+
+  // Invalid depth (pixels with value 0) mapped to black.
+  depth_color.rgb *= sign(depth_meters);
   gl_FragColor = depth_color;
 }