Wrong instance count in subsubmodels with CONSOLIDATE_INSTANCE_COUNT AT_TOP

[sponce]

Subject

When having a complex setup where a subsubmodle is included in different submodels and these submodels are inserted several times in the main model, the instance count for the subsubmodel is wrong.

Environment

• Version of LPub3D : dev-release 2.4.2 revision 40 build 2472 hash e7c39cd
• Operating system : linux debian,x86_64

Screenshots

• Configuration->Preferences->General
• Configuration->Preferences->Rendering
• Configuration->Preferences->Publishing
• Configuration->Preferences->Logging
• Configuration->Preferences->Other

Steps to reproduce

Just open the attached test.mpd file. First page shows a count of 3 when it should be 4.

Expected behaviour

Count on first page should be 4.

Actual behaviour

Count is 3, seems to be that it forgets that test2 is included twice at the top level, as including it only once still gives 3, which is correct in this case.
In other words, when having subsubmodels, it looks like the number of top level inclusions are not counted and multiplied by the number of lower level ones.

Workaround

Simply force the number by hand via "0 !LPUB PAGE SUBMODEL_INSTANCE_COUNT_OVERRIDE 4"

Solution suggestion

I can try to fix it in the code myself. Did not have time to look at it yet.

[trevorsandy]

Thank you for reporting this behaviour.

Indeed, there may be instance count edge cases that are not calculated as there are so many combinations of submodel inclusions possible. There are even cases where the correct number of modelled instances has to be overridden to reflect the actual physical build requirements.

Untreated cases are precisely the reason for the count override command 0 !LPUB PAGE SUBMODEL_INSTANCE_COUNT_OVERRIDE <number>

However, my approach is to add edge cases, if reasonable, as they are reported so I will take a look.

Please provide the steps to reproduce or an example model file that reproduces this behaviour.

Just open the attached test.mpd file. First page shows a count of 3 when it should be 4.

There is no attachment.

Cheers,

[sponce]

Damn I did not notice the file did not attach because .mpd is unknown extension. Sorry. Here it is now.

test.mpd.txt

[sponce]

By the way, I do not think this is particularly urgent and I'm happy to look at it when I manage to find some time.

[trevorsandy]

By the way, I do not think this is particularly urgent and I'm happy to look at it when I manage to find some time.

Very well.

Cheers,

[trevorsandy]

The case presented in your example model file is not an edge case, the current LPub3D countInstances behaviour should produce 4 instances of test3.ldr.

I’ll take a look.

Cheers,

[trevorsandy]

I found the reason for this behaviour.

When a submodel instance is encountered for the first time, I set a flag stating it has been counted, when the submodel is encountered again, its instance count is automatically incremented and the loop continues on to the next line. This approach optimizes performance by avoiding having to parse the same submodel every time it is encountered. However, if that submodel includes a submodel (as in your case), the included submodel instance will not be counted.

Although this is not an edge case, enabling it in the current instance count call will have a significant impact on performance. If I can come up with a routine that preserves performance and captures included submodel instances on subsequent encounters, I'll update the count instance call. Otherwise, this case will simply have to use the override command. Performance is important for the count instance call as it is triggered at every page transition.

Cheers,

[sponce]

Thanks for the quick analysis. In case we stay with the override command, I would then suggest a small modification of a few lines, namely :

• lpub3d/mainApp/traverse.cpp

  Line 1806 in e7c39cd

  displayInstanceCount = countInstances && instances > 1;

• lpub3d/mainApp/traverse.cpp

  Line 2355 in e7c39cd

  displayInstanceCount = steps->meta.LPub.subModel.showInstanceCount.value() && instances > 1;

• lpub3d/mainApp/traverse.cpp

  Line 2496 in e7c39cd

  displayInstanceCount = countInstances && instances > 1;

  
  The thing is that due to the instances > 1 part, override has no effect if the initial count was 1, and there is then no known work-around to the problem in such cases. Probably a simple and || override is set` would be sufficient.

[trevorsandy]

I'll add your suggestion as if the override value is > 1. I also decided to update the countInstance call with the following:

1. Add _subFileIndexes type (Vector<int>) to LDrawSubFile class
2. If a SubFile contains a SubFile, add the child SubFile index to the parent _subFileIndexes :

const int subFileIndex = getSubmodelIndex(tokens[14]);
if (!f->_subFileIndexes.contains(subFileIndex))
    f->_subFileIndexes.append(subFileIndex);

3. When the parent SubFile is automatically incremented, also check for children:

for (int i = 0; i < f->_subFileIndexes.size(); i++)  {
    QMap<QString, LDrawSubFile>::iterator s = _subFiles.find(getSubmodelName(f->_subFileIndexes.at(i)));
    if (s != _subFiles.end())
        ++s->_instances;
}

Result from your example file:

Before update count elapsed time: 0.039 second
After update count elapsed time: 0.050 second

Cheers,

[sponce]

Excellent ! thanks a lot for the fast fix.

[trevorsandy]

I forgot to mention. This is all you need for your example file to be correct.

0 FILE test.ldr
0 Name: test.ldr
0 !LPUB PAGE SIZE GLOBAL 11.75 8.25
0 !LPUB CONSOLIDATE_INSTANCE_COUNT GLOBAL AT_TOP
1 0 -40 0 100 1 0 0 0 1 0 0 0 1 test2.ldr
1 0  40 0 100 1 0 0 0 1 0 0 0 1 test2.ldr
1 0   0 0  50 1 0 0 0 1 0 0 0 1 test1.ldr
0 STEP
0 NOFILE
0 FILE test2.ldr
0 Name: test2.ldr
1 0 0  0 0 1 0 0 0 1 0 0 0 1 test3.ldr
1 2 0 24 0 1 0 0 0 1 0 0 0 1 3001.dat
0 NOFILE
0 FILE test1.ldr
0 Name: test1.ldr
1 0 0   0 -10 1 0 0 0 1 0  0 0 1 test3.ldr
1 0 0   0 110 1 0 0 0 1 0  0 0 1 test3.ldr
1 0 0 -32  50 0 0 1 0 1 0 -1 0 0 3034.dat
0 NOFILE
0 FILE test3.ldr
0 Name: test3.ldr
1  1 0   0 0 1 0 0 0 1 0 0 0 1 3001.dat
1 71 0 -24 0 1 0 0 0 1 0 0 0 1 3001.dat
0 NOFILE

Cheers,