如何让Android Render Script Group工作？

我可以让两个独立的内在函数工作,但不能在ScriptGroup中一起工作.我发现有关如何使用Script Group的文档非常稀疏.

这是我的代码：

        mRS = RenderScript.create(getActivity());

        mInAlLOCATIOn = AlLOCATIOn.createFromBitmap(mRS,mBitmapIn,AlLOCATIOn.MipmapControl.MIPMAP_NONE,AlLOCATIOn.USAGE_SCRIPT |
                        AlLOCATIOn.USAGE_GRAPHICS_TEXTURE|
                        AlLOCATIOn.USAGE_SHARED
        );

        mOutAlLOCATIOn = AlLOCATIOn.createFromBitmap(mRS,mBitmapOut,AlLOCATIOn.USAGE_SCRIPT |
                        AlLOCATIOn.USAGE_SHARED);

        ScripTintrinsicColorMatrix gray = ScripTintrinsicColorMatrix.create(mRS,Element.U8_4(mRS));
        gray.setGreyscale();


        ScripTintrinsicBlur blur = ScripTintrinsicBlur.create(mRS,Element.U8_4(mRS));
        blur.seTradius(20.f);
        blur.seTinput(mInAlLOCATIOn);

        //gray.forEach(mInAlLOCATIOn,mOutAlLOCATIOn);
        blur.forEach(mOutAlLOCATIOn);

        mOutAlLOCATIOn.copyTo(mBitmapOut);

灰色和模糊都有效.然后我尝试将它们放在一起,结果是空白的.码：

       // gray.forEach(mInAlLOCATIOn,mOutAlLOCATIOn);
       // blur.forEach(mOutAlLOCATIOn);
       // mOutAlLOCATIOn.copyTo(mBitmapOut);

        ScriptGroup.builder builder = new ScriptGroup.builder(mRS);

        builder.addKernel(gray.getKernelID());
        builder.addKernel(blur.getKernelID());

        builder.addConnection(mInAlLOCATIOn.getType(),gray.getKernelID(),blur.getKernelID());

        ScriptGroup group = builder.create();

        group.seTinput(gray.getKernelID(),mInAlLOCATIOn);
        group.setOutput(blur.getKernelID(),mOutAlLOCATIOn);

        group.execute();

        mOutAlLOCATIOn.copyTo(mBitmapOut);