Although the Blitter object had the Alpha component, setting it made no difference. Setting Blitter alpha now impacts the rendering of all children, in both Canvas and WebGL, and you can also specify an alpha per Bob as well.

Author: photonstorm

src/renderer/webgl/pipelines/TextureTintPipeline.js

@@ -665,6 +665,8 @@ var TextureTintPipeline = new Class({
 
         var prevTextureSourceIndex;
 
+        var alpha = camera.alpha * blitter.alpha;
+
         for (var batchIndex = 0; batchIndex < batchCount; ++batchIndex)
         {
             var batchSize = Math.min(length, this.maxQuads);
@@ -673,15 +675,15 @@ var TextureTintPipeline = new Class({
             {
                 var bob = list[batchOffset + index];
                 var frame = bob.frame;
-                var alpha = bob.alpha;
+                var bobAlpha = bob.alpha * alpha;
 
-                if (alpha === 0)
+                if (bobAlpha === 0)
                 {
                     //  Nothing to see here, moving on ...
                     continue;
                 }
 
-                var tint = getTint(0xffffff, alpha);
+                var tint = getTint(0xffffff, bobAlpha);
                 var uvs = frame.uvs;
                 var flipX = bob.flipX;
                 var flipY = bob.flipY;