Adding a few more howto elements to scenegraph example.

// This is where the scenegraph and the rendered objects are initialized and used

public class SimpleAppRS {

    private static String TAG = "SimpleAppRS";

    SceneManager mSceneManager;

    RenderScriptGL mRS;

    Scene mScene;

    Mesh mSimpleMesh;

    Mesh mSphereMesh;

    Mesh mCubeMesh;

    public void init(RenderScriptGL rs, Resources res, int width, int height) {

        mRS = rs;

        mScene = new Scene();

        setupGeometry();

        setupRenderables();

        setupColoredQuad();

        setupTexturedQuad();

        setupShadedGeometry();

        setupCamera();

        setupRenderPass();

        Mesh.TriangleMeshBuilder tmb = new Mesh.TriangleMeshBuilder(mRS, 3,

                                                         Mesh.TriangleMeshBuilder.TEXTURE_0);

        // Create four vertices with texture coordinates

        tmb.setTexture(0.0f, 1.0f).addVertex(-1.0f, 1.0f, 0.0f);

        tmb.setTexture(0.0f, 0.0f).addVertex(-1.0f, -1.0f, 0.0f);

        tmb.setTexture(1.0f, 0.0f).addVertex(1.0f, -1.0f, 0.0f);

        tmb.addTriangle(0, 1, 2);

        tmb.addTriangle(2, 3, 0);

        mSimpleMesh = tmb.create(true);

        // Load a file that constains two pieces of geometry, a sphere and a cube

        FileA3D model = FileA3D.createFromResource(mRS, mRes, R.raw.unit_obj);

        for (int i = 0; i < model.getIndexEntryCount(); i ++) {

            FileA3D.IndexEntry entry = model.getIndexEntry(i);

            if (entry != null && entry.getName().equals("CubeMesh")) {

                mCubeMesh = entry.getMesh();

            } else if (entry != null && entry.getName().equals("SphereMesh")) {

                mSphereMesh = entry.getMesh();

            }

        }

    }

    private void setupRenderables() {

    private void setupColoredQuad() {

        // Built-in shader that provides position, texcoord and normal

        VertexShader genericV = SceneManager.getDefaultVS();

        // Built-in shader that displays a color

        FragmentShader colorF = SceneManager.getColorFS();

        // Built-in shader that displays a texture

        FragmentShader textureF = SceneManager.getTextureFS();

        RenderState colorRS = new RenderState(genericV, colorF, null, null);

        ProgramStore alphaBlend = ProgramStore.BLEND_ALPHA_DEPTH_TEST(mRS);

        RenderState texRS = new RenderState(genericV, textureF, alphaBlend, null);

        // Draw a simple colored quad

        Renderable quad = mScene.appendNewRenderable();

        quad.setMesh(mSimpleMesh);

        // Our shader has a constant input called "color"

        // This tells the scenegraph to assign the following float3 to that input

        quad.appendSourceParams(new Float4Param("color", 0.2f, 0.3f, 0.4f));

        quad.setRenderState(colorRS);

    }

    private void setupTexturedQuad() {

        // Built-in shader that provides position, texcoord and normal

        VertexShader genericV = SceneManager.getDefaultVS();

        // Built-in shader that displays a texture

        FragmentShader textureF = SceneManager.getTextureFS();

        // We want to use transparency based on the alpha channel of the texture

        ProgramStore alphaBlend = ProgramStore.BLEND_ALPHA_DEPTH_TEST(mRS);

        RenderState texRS = new RenderState(genericV, textureF, alphaBlend, null);

        // Draw a textured quad

        quad = mScene.appendNewRenderable();

        Renderable quad = mScene.appendNewRenderable();

        quad.setMesh(mSimpleMesh);

        // Make a transform to position the quad

        CompoundTransform t = mScene.appendNewCompoundTransform();

        t.addTranslate("position", new Float3(2, 2, 0));

        quad.setTransform(t);

        // Our fragment shader has a constant texture input called "color"

        // This will assign an icon from drawables to that input

        quad.appendSourceParams(new TextureParam("color", new Texture2D(R.drawable.icon)));

        quad.setRenderState(texRS);

    }

    private FragmentShader createLambertShader() {

        // Describe what constant inputs our shader wants

        Element.Builder b = new Element.Builder(mRS);

        b.add(Element.F32_4(mRS), "cameraPos");

        // Create a shader from a text file in resources

        FragmentShader.Builder fb = new FragmentShader.Builder(mRS);

        // Tell the shader what constants we want

        fb.setShaderConst(new Type.Builder(mRS, b.create()).setX(1).create());

        // Shader code location

        fb.setShader(mRes, R.raw.diffuse);

        // We want a texture called diffuse on our shader

        fb.addTexture(TextureType.TEXTURE_2D, "diffuse");

        FragmentShader shader = fb.create();

        mScene.appendShader(shader);

        return shader;

    }

    private void setupShadedGeometry() {

        // Built-in shader that provides position, texcoord and normal

        VertexShader genericV = SceneManager.getDefaultVS();

        // Custom shader

        FragmentShader diffuseF = createLambertShader();

        RenderState diffuseRS = new RenderState(genericV, diffuseF, null, null);

        // Draw a sphere

        Renderable sphere = mScene.appendNewRenderable();

        // Use the sphere geometry loaded earlier

        sphere.setMesh(mSphereMesh);

        // Make a transform to position the sphere

        CompoundTransform t = mScene.appendNewCompoundTransform();

        t.addTranslate("position", new Float3(-1, 2, 3));

        t.addScale("scale", new Float3(1.4f, 1.4f, 1.4f));

        sphere.setTransform(t);

        // Tell the renderable which texture to use when we draw

        // This will mean a texture param in the shader called "diffuse"

        // will be assigned a texture called red.jpg

        sphere.appendSourceParams(new TextureParam("diffuse", new Texture2D("", "red.jpg")));

        sphere.setRenderState(diffuseRS);

        // Draw a cube

        Renderable cube = mScene.appendNewRenderable();

        cube.setMesh(mCubeMesh);

        t = mScene.appendNewCompoundTransform();

        t.addTranslate("position", new Float3(-2, -2.1f, 0));

        t.addRotate("rotateX", new Float3(1, 0, 0), 30);

        t.addRotate("rotateY", new Float3(0, 1, 0), 30);

        t.addScale("scale", new Float3(2, 2, 2));

        cube.setTransform(t);

        cube.appendSourceParams(new TextureParam("diffuse", new Texture2D("", "orange.jpg")));

        cube.setRenderState(diffuseRS);

    }

    private void setupCamera() {

        Camera camera = mScene.appendNewCamera();

        camera.setFar(200);