Mexing chai3d

Hi! I have tried to create a .cpp using chai3d libraries and compile it in MATLAB via mex engine. But it looks like MATLAB connot recognise every chai3d file because it returns import errors. I am very lost with this task and any help will be really greatful.

[Jan]

You forgot to mention any details. Which input files cause which error? Which libraries are you using?

Answer 1

[Carlos Martinez Suarez]

Hello, thanks for answering and sorry for not giving enough details, I'll try to explain it better.

I have downloaded the chai3d libraries from its official page: https://www.chai3d.org/download/releases

Then I have taken an example from MATLAB that compiles and works perfectly when using mex with Microsoft Visual 2017 c++ compiler (the compiler needed for chai3d).

Then I copy that example (called "prueba.cpp") in the folder where the chai3d libraries are downloaded:

Finally, I just add a line including the chai3d.h file: #include "chai3d.h". Here is where the problems come. When I try compiling after adding that line, MATLAB returns an error saying that chai3d.h cannot be found. This is solved changing the include sentence into #include "src/chai3d.h" as long as it is the right path. I do not really understand why I have to specify the full path when I added every folder to MATLAB paths.

When compiling with "src/chai3d.h", it returns another error that says that in one of the files of the library it cannot be found some files and this happens over and over when fixing the previous errors.

Thanks for answering so fast and I hope you can help me.

Example:

#include "mex.hpp"
#include "mexAdapter.hpp"

using namespace matlab::data;
using matlab::mex::ArgumentList;
using namespace std;

class MexFunction : public matlab::mex::Function {
public:
    void operator()(ArgumentList outputs, ArgumentList inputs) {
        checkArguments(outputs, inputs);
       
        const double offSet = inputs[0][0];
        TypedArray<double> doubleArray = std::move(inputs[1]);
        for (auto& elem : doubleArray) {
            elem += offSet;
        }
        outputs[0] = doubleArray;
    }

    void checkArguments(ArgumentList outputs, ArgumentList inputs) {
        // Get pointer to engine
        std::shared_ptr<matlab::engine::MATLABEngine> matlabPtr = getEngine();

        // Get array factory
        ArrayFactory factory;

        // Check first input argument
        if (inputs[0].getType() != ArrayType::DOUBLE ||
            inputs[0].getType() == ArrayType::COMPLEX_DOUBLE ||
            inputs[0].getNumberOfElements() != 1)
        {
            matlabPtr->feval(u"error",
                0,
                std::vector<Array>({ factory.createScalar("First input must scalar double") }));
        }

        // Check second input argument
        if (inputs[1].getType() != ArrayType::DOUBLE ||
            inputs[1].getType() == ArrayType::COMPLEX_DOUBLE)
        {
            matlabPtr->feval(u"error",
                0,
                std::vector<Array>({ factory.createScalar("Input must double array") }));
        }
        // Check number of outputs
        if (outputs.size() > 1) {
            matlabPtr->feval(u"error",
                0,
                std::vector<Array>({ factory.createScalar("Only one output is returned") }));
        }
    }
};