How to set up Assimp for Qt6 MinGW 64-bit

[8Observer8]

The next steps work for me (after I added C:\emsdk\upstream\emscripten to the Path variable):

@shome said in qmake for wasm unable to find opengl libraries:

which I have built using emscripten using the following steps:

git clone https://github.com/assimp/assimp.git
cd assimp && mkdir build && cd build
emcmake cmake ..
emmake make

These commands generated the libassimp.a library:

I try to set up this library in Qt Creator like this:

INCLUDEPATH += "E:/libs/assimp-5.2.5/include"
LIBS += -L"E:/libs/assimp-5.2.5/build/lib"
LIBS += -lassimp

I had this error: error: 'assimp/config.h' file not found. I solved this error by copying this file E:\libs\assimp-5.2.5\build\include\assimp\config.h to this directory: E:\libs\assimp-5.2.5\include\assimp.

Now I have the next error :-1: error: [Makefile:69: .\load-with-assimp-wasm-opengles2-qt6-cpp.js] Error 1 But I have already built another examples with OpenGL ES 2.0 without the problem.

load-with-assimp-wasm-opengles2-qt6-cpp.pro

QT += core gui openglwidgets widgets

win32: LIBS += -lopengl32

INCLUDEPATH += "E:/libs/assimp-5.2.5/include"
LIBS += -L"E:/libs/assimp-5.2.5/build/lib"
LIBS += -lassimp

CONFIG += c++11

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# disables all the APIs deprecated before Qt 6.0.0
DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000

SOURCES += \
    main.cpp

main.cpp

#include <QtCore/QDebug>
#include <QtGui/QMatrix4x4>
#include <QtGui/QVector3D>
#include <QtGui/QOpenGLFunctions>
#include <QtOpenGL/QOpenGLBuffer>
#include <QtOpenGL/QOpenGLShaderProgram>
#include <QtOpenGLWidgets/QOpenGLWidget>
#include <QtWidgets/QApplication>
#include <QtWidgets/QMessageBox>

#include <assimp/Importer.hpp>
#include <assimp/postprocess.h>
#include <assimp/scene.h>

class OpenGLWidget : public QOpenGLWidget, private QOpenGLFunctions
{
public:
    OpenGLWidget()
    {
        setWindowTitle("Qt C++, OpenGL");
        resize(400, 400);
    }

private:
    QOpenGLBuffer m_vertPosBuffer;
    QOpenGLShaderProgram m_program;
    int m_numVertices;
    QMatrix4x4 m_modelMatrix;

    void initializeGL() override
    {
        initializeOpenGLFunctions();
        glClearColor(0.1f, 0.1f, 0.1f, 1.f);
        glEnable(GL_DEPTH_TEST);

        Assimp::Importer importer;
        const char *path = "assets/models/plane-blender.dae";
        const aiScene *scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_FlipUVs);
        if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode)
        {
            qDebug() << "Assimp Error:" << importer.GetErrorString();
            QMessageBox::critical(this, "Assimp Error:", importer.GetErrorString());
            return;
        }

        m_numVertices = scene->mMeshes[0]->mNumVertices;
        float vertPositions[m_numVertices * 3];
        int vertPosIndex = 0;
        for (int i = 0; i < m_numVertices; i++)
        {
            vertPositions[vertPosIndex++] = scene->mMeshes[0]->mVertices[i].x;
            vertPositions[vertPosIndex++] = scene->mMeshes[0]->mVertices[i].y;
            vertPositions[vertPosIndex++] = scene->mMeshes[0]->mVertices[i].z;
           // qDebug() << scene->mMeshes[0]->mVertices[i].x << ", "
           //          << scene->mMeshes[0]->mVertices[i].y << ", "
           //           << scene->mMeshes[0]->mVertices[i].z;
           //  qDebug() << "\n";
        }
        m_vertPosBuffer.create();
        m_vertPosBuffer.bind();
        m_vertPosBuffer.allocate(vertPositions, sizeof(vertPositions));

        const char *vertShaderSrc =
            "attribute vec3 aPosition;"
            "uniform mat4 uModelMatrix;"
            "void main()"
            "{"
            "    gl_Position = uModelMatrix * vec4(aPosition, 1.0);"
            "}";
        const char *fragShaderSrc =
            "void main()"
            "{"
            "    gl_FragColor = vec4(0.5, 0.2, 0.7, 1.0);"
            "}";
        m_program.create();
        m_program.addShaderFromSourceCode(QOpenGLShader::ShaderTypeBit::Vertex,
            vertShaderSrc);
        m_program.addShaderFromSourceCode(QOpenGLShader::ShaderTypeBit::Fragment,
            fragShaderSrc);
        m_program.link();
    }

    void resizeGL(int w, int h) override
    {
        glViewport(0, 0, w, h);
    }

    void paintGL() override
    {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        m_modelMatrix.setToIdentity();
        m_modelMatrix.scale(0.5);
        m_program.bind();
        m_program.setUniformValue("uModelMatrix", m_modelMatrix);
        m_vertPosBuffer.bind();
        m_program.setAttributeBuffer("aPosition", GL_FLOAT, 0, 3);
        m_program.enableAttributeArray("aPosition");
        glDrawArrays(GL_TRIANGLES, 0, m_numVertices);
    }
};

int main(int argc, char *argv[])
{
    QApplication::setAttribute(Qt::ApplicationAttribute::AA_UseDesktopOpenGL);
    QApplication app(argc, argv);
    OpenGLWidget w;
    w.show();
    return app.exec();
}

[8Observer8]

@jsulm I built zlib with these commands:

cd zlib-1.3.1 && mkdir build && cd build
emcmake cmake ..
emmake make

libz.a (245 KB) was generated.

I set up it like this:

LIBS += -L"E:\libs\zlib-1.3.1\lib"
LIBS += -lz

Now it compiles. But I think Assimp must include zlib. A size of libassimp.a is 89.3 MB.

I have this error now:

I had a problem with loading models from Qt Resources with Assimp: Loading a 3D model from Qt Resources. Assimp Error: No suitable reader found for the file format of file I decided do not use Qt Resources to solve that problem. But now I don't know how to solve it for WASM.

[jsulm]

@8Observer8 said in How to set up Assimp for Qt6 MinGW 64-bit:

Now I have the next error :-1: error: [Makefile:69: .\load-with-assimp-wasm-opengles2-qt6-cpp.js] Error 1

Please post the actual error

[8Observer8]

@jsulm Qt Creator shows only this error:

[jsulm]

@8Observer8 There should be more in the "Compile Output" tab.

[8Observer8]

Compiler output:

wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(AssbinLoader.cpp.o): undefined symbol: uncompress
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateInit_
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateInit2_
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflate
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflate
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflate
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateReset
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateSetDictionary
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateEnd
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateEnd
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflateInit2_
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(unzip.c.o): undefined symbol: get_crc_table
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(unzip.c.o): undefined symbol: crc32
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(Compression.cpp.o): undefined symbol: inflate
wasm-ld: error: E:/libs/assimp-5.2.5/build/lib\libassimp.a(unzip.c.o): undefined symbol: crc32
em++: error: 'C:/emsdk/upstream/bin\wasm-ld.exe -o .\load-with-assimp-wasm-opengl2-qt6-cpp.wasm C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledFreetype.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledLibpng.a main.obj load-with-assimp-wasm-opengl2-qt6-cpp.js_plugin_import.obj -LE:/libs/assimp-5.2.5/build/lib E:/libs/assimp-5.2.5/build/lib\libassimp.a C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/QWasmIntegrationPlugin_resources_1/.rcc/qrc_wasmfonts_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/QWasmIntegrationPlugin_resources_2/.rcc/qrc_wasmwindow_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Gui_resources_1/.rcc/qrc_qpdf_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Gui_resources_2/.rcc/qrc_gui_shaders_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/plugins/platforms/libqwasm.a C:/Qt/6.7.0/wasm_singlethread/plugins/iconengines/libqsvgicon.a C:/Qt/6.7.0/wasm_singlethread/plugins/imageformats/libqgif.a C:/Qt/6.7.0/wasm_singlethread/plugins/imageformats/libqico.a C:/Qt/6.7.0/wasm_singlethread/plugins/imageformats/libqjpeg.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledLibjpeg.a C:/Qt/6.7.0/wasm_singlethread/plugins/imageformats/libqsvg.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6Svg.a C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Widgets_resources_1/.rcc/qrc_qstyle_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Widgets_resources_2/.rcc/qrc_qstyle1_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Widgets_resources_3/.rcc/qrc_qstyle_fusion_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/objects-Release/Widgets_resources_4/.rcc/qrc_qmessagebox_init.cpp.o C:/Qt/6.7.0/wasm_singlethread/lib/libQt6OpenGLWidgets.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6OpenGL.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6Widgets.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6Gui.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledHarfbuzz.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledFreetype.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledLibpng.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6Core.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledZLIB.a C:/Qt/6.7.0/wasm_singlethread/lib/libQt6BundledPcre2.a -LC:\emsdk\upstream\emscripten\cache\sysroot\lib\wasm32-emscripten --whole-archive -lfetch -lembind-rtti --no-whole-archive -lGL-webgl2 -lal -lhtml5 -lstubs-debug -lnoexit -lc-debug -ldlmalloc -lcompiler_rt -lc++-noexcept -lc++abi-debug-noexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr C:\Users\8OBSER~1\AppData\Local\Temp\tmp1971j9eilibemscripten_js_symbols.so --export-if-defined=main --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=__main_argc_argv --export-if-defined=fflush --export=emscripten_stack_get_end --export=emscripten_stack_get_free --export=emscripten_stack_get_base --export=emscripten_stack_get_current --export=emscripten_stack_init --export=__cxa_demangle --export=stackSave --export=stackRestore --export=stackAlloc --export=__errno_location --export=malloc --export=free --export=__wasm_call_ctors --export-table -z stack-size=5242880 --initial-memory=52428800 --no-entry --max-memory=2147483648 --stack-first' failed (returned 1)
mingw32-make: *** [Makefile:69: .\load-with-assimp-wasm-opengl2-qt6-cpp.js] Error 1
15:05:07: The process "C:\Qt\Tools\mingw1120_64\bin\mingw32-make.exe" exited with code 2.
Error while building/deploying project load-with-assimp-wasm-opengl2-qt6-cpp (kit: WebAssembly Qt 6.7.0 (single-threaded))
When executing step "Make"

[8Observer8]

I created the same topics on Assimp discussions: https://github.com/assimp/assimp/discussions/5515 and Stack Overflow: https://stackoverflow.com/questions/78230555/how-to-set-up-assimp-for-qt6-mingw-64-bit-to-run-on-webassembly

[jsulm]

@8Observer8 Would be good to get the very first error, but it looks like a library is not found or is incompatible

[8Observer8]

Botje wrote the next comment on StackOverflow:

Those are functions from zlib.

[jsulm]

@8Observer8 libassimp depends on zlib, so if there is no zlip it will not work

[8Observer8]

@jsulm I built zlib with these commands:

cd zlib-1.3.1 && mkdir build && cd build
emcmake cmake ..
emmake make

libz.a (245 KB) was generated.

I set up it like this:

LIBS += -L"E:\libs\zlib-1.3.1\lib"
LIBS += -lz

Now it compiles. But I think Assimp must include zlib. A size of libassimp.a is 89.3 MB.

I have this error now:

I had a problem with loading models from Qt Resources with Assimp: Loading a 3D model from Qt Resources. Assimp Error: No suitable reader found for the file format of file I decided do not use Qt Resources to solve that problem. But now I don't know how to solve it for WASM.

[8Observer8]

Botje wrote the next comment on Stack Overflow:

libassimp.a does not contain zlib. If you inspect the makefile generated by cmake you will see it just collects all the object files and does not add libz in any way. That is reserved for the final step where your application links to libassimp.a, because other dependencies might also need zlib and if each brings its own copy you get conflicts.