trouble finding sampler "OUTPUT" data

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1

I’m trying to figure out how to drill into the <animation> object and extract the data for each sampler. The code below is my loop to run through all the samplers and extract the position data from the “OUTPUT” array into a domListOfFloats.

I’ve found that the sampler gets loaded and read correctly, but that it always fails the check against the semantic “OUTPUT.” The output array of floats is the one I need–the one with the 4x4 matrices. This code is almost line-for-line the copy of my geometry extraction code, and that works just fine. What do I need to do differently to get the right data out of the sampler?

   for (int currentSampler = 0; currentSampler < numSamplers; currentSampler++) {
      domSource* source;

      // Get current sampler
      domSampler *sampler = animation->getSampler_array()[currentSampler];


      domInputLocal_Array inputArray = sampler->getInput_array();
      domInputLocalRef inputRef = inputArray[currentSampler]; 

      // Resolve the element
      inputRef->getSource().resolveElement();
      daeElement* element = inputRef->getSource().getElement();

      source = (domSource*)element;

      // Get the accessor
      domAccessorRef accessor = source->getTechnique_common()->getAccessor();

      // Extract the data
      
      if (strcmp(inputRef->getSemantic(), "OUTPUT") == 0) {
         samplerData = source->getFloat_array()->getValue();
         stride = (int)accessor->getStride();
         numSamples = (int)accessor->getCount();
      }

Something interesting I found was that, if I remove the if statement from around the last block, my function successfully returns the data from the “INPUT” attribute inside <animation>. I assume that’s the default setting?

2

Your code looks correct to me. I would try stepping through the code in a debugger and making sure there is in fact an <input semantic=“OUTPUT” …/> element in the array you’re iterating over.

Steve

3

I’m certain there is. I’ve opened the .dae file that we’re using, and I can see it at the bottom. Looks like this:

      <sampler id="joint2.matrix_joint2_transform-sampler">
        <input semantic="INPUT" source="#joint2.matrix_joint2_transform-input"/>
        <input semantic="OUTPUT" source="#joint2.matrix_joint2_transform-output"/>
        <input semantic="INTERPOLATION" source="#joint2.matrix_joint2_transform-interpolations"/>
      </sampler>

Is there something else I need to do in my code to specify that it’s the OUTPUT array I want to tap?

4

If you step through your code in a debugger you can probably figure out what’s going wrong.

5

I just wrote some test code for this. There’s definitely something fishy going on. Every <input> reports that its semantic is “OUTPUT”, which certainly isn’t right. I’ll let you know what I figure out.

Steve

6

Actually, scratch that last post. I had a bug in my indexing. But I found what was wrong with your code.

// Get current sampler
domSampler *sampler = animation->getSampler_array()[currentSampler];

domInputLocal_Array inputArray = sampler->getInput_array();
domInputLocalRef inputRef = inputArray[currentSampler];

You’re using the same index into the <input> array that you’re using for the <sampler> array. The sampler contains an array of <input>s so you have to iterate over them separately.

Also, to avoid making a copy of the <input> array, use a reference variable:
domInputLocal_Array& inputArray = sampler->getInput_array();

7

Unfortunately, I can’t break and debug because we’re running the plugin from within Refinery, and not from within the IDE. But, you were dead right about the need for a separate loop. It works just fine now, thank you very much!