I try to use GL_TEXTURE_3D with Ofelia. No luck with that so far. But there is one addon https://github.com/timscaffidi/ofxVolumetrics which does what I want with Open Frameworks (this example does work: https://github.com/totetmatt/TLCube). My question is how to add addons to Ofelia. And if it is not possible, how to add and use a GL_TEXTURE_3D without addons.
The idea behind my attempts is to make a 3d game of life that runs on the GPU.

A nice finding is that it is easily possible to bind openGL functions (like any other C++ functions) to Ofelia:
Just add a function to ofxOfeliaPdBindings.h like:

static int pdGlMaxShaderStorageBlockSize()
{
    int gi = 0;
    return glGetIntegerv(GL_MAX_SHADER_STORAGE_BLOCK_SIZE, &gi);
}

run updatePdBindings.sh, and compile the Ofelia external.
Then you can call ofGlMaxShaderStorageBlockSize() from PD with Ofelia.

I tried this for the 3d texture (it does not work yet):

static t_float pdTexture3d(float sizeX, float sizeY, float sizeZ)
{
    GLuint textureId = 0;
    glGenTextures(1, &textureId);
    glBindTexture(GL_TEXTURE_3D, textureId);
    glTexStorage3D(GL_TEXTURE_3D, 1, GL_RGB8, sizeX, sizeY, sizeZ);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);   
    error("textureId '%i'", textureId);
    return textureId;
}

actually most openGL methods are already bound to Ofelia, for example:

ofelia f;
print (GL_MAX_SHADER_STORAGE_BLOCK_SIZE);

but not something like:

glEnable(GL_TEXTURE_3D);

in ofxOfeliaGL.cpp are all accessable methods.

i think i learned how to integrate addons (not everything is working yet...).
this is what i added to ofxOfeliaPdBindings.h to integrate ofxVolumetrics:

class pdTexture3d
{
public:
    pdTexture3d(){};

    void allocate(int w, int h, int d, int internalGlDataType)
    {
        texture3d.allocate(w, h, d, internalGlDataType);
    }

    void loadData(unsigned char * data, int w, int h, int d, int xOffset, int yOffset, int zOffset, int glFormat)
    {
        texture3d.loadData(data, w, h, d, xOffset, yOffset, zOffset, glFormat);
    }

    void loadData(float* data, int w, int h, int d, int xOffset, int yOffset, int zOffset, int glFormat)
    {
        texture3d.loadData(data, w, h, d, xOffset, yOffset, zOffset, glFormat);
    }

    void loadData(unsigned short* data, int w, int h, int d, int xOffset, int yOffset, int zOffset, int glFormat)
    {
        texture3d.loadData(data, w, h, d, xOffset, yOffset, zOffset, glFormat);
    }

    void loadData(ofPixels & pix, int d, int xOffset, int yOffset, int zOffset)
    {
        texture3d.loadData(pix, d, xOffset, yOffset, zOffset);
    }

    void loadData(ofShortPixels & pix, int d, int xOffset, int yOffset, int zOffset)
    {
        texture3d.loadData(pix, d, xOffset, yOffset, zOffset);
    }

    void loadData(ofFloatPixels & pix, int d, int xOffset, int yOffset, int zOffset)
    {
        texture3d.loadData(pix, d, xOffset, yOffset, zOffset);
    }

    void bind()
    {
        texture3d.bind();
    }

    void unbind()
    {
        texture3d.unbind();
    }

    void clear()
    {
        texture3d.clear();
    }

    ofxTextureData3d getTextureData()
    {
        return texture3d.getTextureData();
    }

private:
    ofxTexture3d texture3d;
};


class pdVolumetrics
{
public:
    pdVolumetrics(){};

    void setup(int w, int h, int d, ofVec3f voxelSize, bool usePowerOfTwoTexSize=false)
    {
        volumetrics.setup(w, h, d, voxelSize, usePowerOfTwoTexSize);
    }

    void destroy()
    {
        volumetrics.destroy();
    }

    void updateVolumeData(unsigned char * data, int w, int h, int d, int xOffset, int yOffset, int zOffset)
    {
        volumetrics.updateVolumeData(data, w, h, d, xOffset, yOffset, zOffset);
    }

    void drawVolume(float x, float y, float z, float size, int zTexOffset)
    {
        volumetrics.drawVolume(x, y, z, size, zTexOffset);
    }

    void drawVolume(float x, float y, float z, float w, float h, float d, int zTexOffset)
    {
        volumetrics.drawVolume(x, y, z, w, h, d, zTexOffset);
    }

    bool isInitialized()
    {
        return volumetrics.isInitialized();
    }

    int getVolumeWidth()
    {
        return volumetrics.getVolumeWidth();
    }

    int getVolumeHeight()
    {
        return volumetrics.getVolumeHeight();
    }

    int getVolumeDepth()
    {
        return volumetrics.getVolumeDepth();
    }
 
    ofFbo & getFboReference()
    {
        return volumetrics.getFboReference();
    }

    int getRenderWidth()
    {
        return volumetrics.getRenderWidth();
    }

    int getRenderHeight()
    {
        return volumetrics.getRenderHeight();
    }

    float getXyQuality()
    {
        return volumetrics.getXyQuality();
    }

    float getZQuality()
    {
        return volumetrics.getZQuality();
    }

    float getThreshold()
    {
        return volumetrics.getThreshold();
    }

    float getDensity()
    {
        return volumetrics.getDensity();
    }

    void setXyQuality(float q)
    {
        volumetrics.setXyQuality(q);
    }

    void setZQuality(float q)
    {
        volumetrics.setZQuality(q);
    }

    void setThreshold(float t)
    {
        volumetrics.setThreshold(t);
    }

    void setDensity(float d)
    {
        volumetrics.setDensity(d);
    }

    void setRenderSettings(float xyQuality, float zQuality, float dens, float thresh)
    {
        volumetrics.setRenderSettings(xyQuality, zQuality, dens, thresh);
    }

    void setVolumeTextureFilterMode(GLint filterMode)
    {
        volumetrics.setVolumeTextureFilterMode(filterMode);
    }

private:
    ofxVolumetrics volumetrics;
};


class pdImageSequencePlayer
{
public:
    pdImageSequencePlayer(){};

    void init(std::string prefix, int digits, std::string extension, int start)
    {
        imageSequencePlayer.init(prefix, digits, extension, start);
    }

    int getWidth()
    {
        return imageSequencePlayer.getWidth();
    }

    int getHeight()
    {
        return imageSequencePlayer.getHeight();
    }

    ofPixels_<unsigned char> getPixels()
    {
        return imageSequencePlayer.getPixels();
    }

    int getSequenceLength()
    {
        return imageSequencePlayer.getSequenceLength();
    }

    bool loadNextFrame()
    {
        return imageSequencePlayer.loadNextFrame();
    }

    bool loadPreviousFrame()
    {
        return imageSequencePlayer.loadPreviousFrame();
    }

    bool loadFrame(int n)
    {
        return imageSequencePlayer.loadFrame(n);
    }

    int getCurrentFrameNumber()
    {
        return imageSequencePlayer.getCurrentFrameNumber();
    }

    void setCurrentFrameNumber(int i)
    {
        imageSequencePlayer.setCurrentFrameNumber(i);
    }

    bool isInitialized()
    {
        return imageSequencePlayer.isInitialized();
    }

private:
    ofxImageSequencePlayer imageSequencePlayer;
};