title: What to make out of the output of QSG_RENDERER_DEBUG=render
body: <p>When I set the environment variable <code>QSG_RENDERER_DEBUG=render</code> , I get the following output:</p>
  
  <pre><code>Renderer::render() QSGAbstractRenderer(0x383865f8) "rebuild: none"
  Rendering:
   -&gt; Opaque: 38 nodes in 2 batches...
   -&gt; Alpha: 34 nodes in 13 batches...
   - 0x3836a830 [retained] [noclip] [opaque] [  merged]  Nodes:   14  Vertices:    88  Indices:   124  root: 0x0
   - 0x3836a7f0 [  upload] [noclip] [opaque] [  merged]  Nodes:   24  Vertices:    96  Indices:   144  root: 0x0
   - 0x3836a8f0 [retained] [noclip] [ alpha] [unmerged]  Nodes:    1  Vertices:    48  Indices:    74  root: 0x0
   - 0x3836a870 [retained] [noclip] [ alpha] [unmerged]  Nodes:    3  Vertices:    52  Indices:    78  root: 0x0
   - 0x3836a8b0 [retained] [noclip] [ alpha] [unmerged]  Nodes:    6  Vertices:   400  Indices:   720  root: 0x0
   - 0x3836a530 [retained] [noclip] [ alpha] [unmerged]  Nodes:    4  Vertices:    56  Indices:    84  root: 0x0
   - 0x3836a570 [retained] [noclip] [ alpha] [  merged]  Nodes:    1  Vertices:     4  Indices:     6  root: 0x0 opacity: 1
   - 0x3836a5b0 [retained] [noclip] [ alpha] [unmerged]  Nodes:    7  Vertices:   720  Indices:  1302  root: 0x0
   - 0x3836a630 [retained] [noclip] [ alpha] [unmerged]  Nodes:    3  Vertices:    28  Indices:    42  root: 0x0
   - 0x3836a5f0 [retained] [noclip] [ alpha] [  merged]  Nodes:    3  Vertices:    12  Indices:    18  root: 0x0 opacity: 1
   - 0x3836a6f0 [retained] [noclip] [ alpha] [  merged]  Nodes:    1  Vertices:     4  Indices:     6  root: 0x0 opacity: 1
   - 0x3836a670 [retained] [noclip] [ alpha] [  merged]  Nodes:    1  Vertices:     4  Indices:     6  root: 0x0 opacity: 1
   - 0x3836a6b0 [retained] [noclip] [ alpha] [  merged]  Nodes:    1  Vertices:     4  Indices:     6  root: 0x0 opacity: 1
   - 0x3836a330 [retained] [noclip] [ alpha] [unmerged]  Nodes:    2  Vertices:    24  Indices:    36  root: 0x0
   - 0x3836a370 [retained] [noclip] [ alpha] [  merged]  Nodes:    1  Vertices:     4  Indices:     6  root: 0x0 opacity: 1
   -&gt; times: build: 0, prepare(opaque/alpha): 0/0, sorting: 0, upload(opaque/alpha): 0/0, render: 1
  </code></pre>
  
  <p>which I deem bad to catastrophal, if I want to run it on a low-performance-device such as an old Raspberry PI.</p>
  
  <p>However I fail to find the answers to: <strong>what to make out of this? How can I improve it, to reduce the amount of batches, especially the Alpha-batches?</strong></p>
  
  <p>I have only few objects (2) with <code>opacity != 0</code> and at the time of this output all of them have been set to invisible.</p>
  
  <p>I have two SVGs (8 nodes each) which might show up there.</p>
  
  <p>I do not use any colors that would not fit in the format <code>'#------ff'</code> (unless the svg-colors of which I use a few might have the alpha-channel set otherwise) and do not use the color <code>'transparent'</code></p>
  
  <p>I do have an object that consists out of two "concentric" <code>Rectangles</code> of opaque color, that are marked <em>unmerged</em> when visualizing the <em>overdraw</em>, which I have no clue, why. At least it could be merged with it's not-intersecting siblings, I deem. <strong>Why wouldn't they?</strong></p>
  
  <p>I think it migh help if I might identify the objects, but when I ouput the adresses of any object that is visible, (<code>Component.onCompleted: console.log(this)</code>) I do not get any of the listed adresses.<br>
  <strong>How might I achieve a mapping between the render-objects and my QML-Objects?</strong></p>
  
  <p>And - <strong>What doe all those list entries mean at all?</strong></p>
  
  <p><strong>EDIT:</strong> It seems, I used some PNG's with alpha enabled. Replacing them with JPG reduced the message to this. But those were only 5 of the nodes/batches. 34 to go...</p>
  
  <pre><code> -&gt; Opaque: 43 nodes in 6 batches...
   -&gt; Alpha: 29 nodes in 8 batches...
  </code></pre>
  
  <p>Greetings &amp; Thanks,<br>
  -m-</p>