1 前言
本文通过一个立方体贴图的例子，讲解三维纹理贴图（子网格贴图）的应用，案例中使用 6 张不同的图片给立方体贴图，图片如下。
读者如果对 Filament 不太熟悉，请回顾以下内容。
2 立方体贴图
本文项目结构如下，完整代码资源 → Filament立方体贴图（6张图）。
2.1 基础类
为方便读者将注意力聚焦在 Filament 的输入上，轻松配置复杂的环境依赖逻辑，笔者仿照 OpenGL ES 的写法，抽出了 FLSurfaceView、BaseModel、Mesh、MaterialUtils 和 TextureUtils 类。FLSurfaceView 与 GLSurfaceView 的功能类似，承载了渲染环境配置；BaseModel 用于管理模型的网格和材质；Mesh 用于管理模型的顶点属性；MaterialUtils 和 TextureUtils 中分别提供了一些材质和纹理相关的工具。
build.gradle
bash
...
android {
...
aaptOptions { // 在应用程序打包过程中不压缩的文件
noCompress 'filamat', 'ktx'
}
}
dependencies {
implementation fileTree(dir: '../libs', include: ['*.aar'])
...
} 说明：在项目根目录下的 libs 目录中，需要放入以下 aar 文件，它们源自Filament环境搭建中编译生成的 aar。
FLSurfaceView.java
java
package com.zhyan8.multitexture.filament;
import android.content.Context;
import android.graphics.Point;
import android.view.Choreographer;
import android.view.Surface;
import android.view.SurfaceView;
import com.google.android.filament.Camera;
import com.google.android.filament.Engine;
import com.google.android.filament.EntityManager;
import com.google.android.filament.Filament;
import com.google.android.filament.Renderer;
import com.google.android.filament.Scene;
import com.google.android.filament.Skybox;
import com.google.android.filament.SwapChain;
import com.google.android.filament.View;
import com.google.android.filament.Viewport;
import com.google.android.filament.android.DisplayHelper;
import com.google.android.filament.android.FilamentHelper;
import com.google.android.filament.android.UiHelper;
import java.util.ArrayList;
/*
* Filament中待渲染的SurfaceView
* 功能可以类比OpenGL ES中的GLSurfaceView
* 用于创建Filament的渲染环境
*/
public class FLSurfaceView extends SurfaceView {
public static int RENDERMODE_WHEN_DIRTY = 0; // 用户请求渲染才渲染一帧
public static int RENDERMODE_CONTINUOUSLY = 1; // 持续渲染
protected int mRenderMode = RENDERMODE_CONTINUOUSLY; // 渲染模式
protected Choreographer mChoreographer; // 消息控制
protected DisplayHelper mDisplayHelper; // 管理Display(可以监听分辨率或刷新率的变化)
protected UiHelper mUiHelper; // 管理SurfaceView、TextureView、SurfaceHolder
protected Engine mEngine; // 引擎(跟踪用户创建的资源, 管理渲染线程和硬件渲染器)
protected Renderer mRenderer; // 渲染器(用于操作系统窗口, 生成绘制命令, 管理帧延时)
protected Scene mScene; // 场景(管理渲染对象、灯光)
protected View mView; // 存储渲染数据(View是Renderer操作的对象)
protected Camera mCamera; // 相机(视角管理)
protected Point mDesiredSize; // 渲染分辨率
protected float[] mSkyboxColor; // 背景颜色
protected SwapChain mSwapChain; // 操作系统的本地可渲染表面(native renderable surface, 通常是一个window或view)
protected FrameCallback mFrameCallback = new FrameCallback(); // 帧回调
protected ArrayList<RenderCallback> mRenderCallbacks; // 每一帧渲染前的回调(一般用于处理模型变换、相机变换等)
static {
Filament.init();
}
public FLSurfaceView(Context context) {
super(context);
mChoreographer = Choreographer.getInstance();
mDisplayHelper = new DisplayHelper(context);
mRenderCallbacks = new ArrayList<>();
}
public void init() { // 初始化
setupSurfaceView();
setupFilament();
setupView();
setupScene();
}
public void setRenderMode(int renderMode) { // 设置渲染模式
mRenderMode = renderMode;
}
public void addRenderCallback(RenderCallback renderCallback) { // 添加渲染回调
if (renderCallback != null) {
mRenderCallbacks.add(renderCallback);
}
}
public void requestRender() { // 请求渲染
mChoreographer.postFrameCallback(mFrameCallback);
}
public void onResume() { // 恢复
mChoreographer.postFrameCallback(mFrameCallback);
}
public void onPause() { // 暂停
mChoreographer.removeFrameCallback(mFrameCallback);
}
public void onDestroy() { // 销毁Filament环境
mChoreographer.removeFrameCallback(mFrameCallback);
mRenderCallbacks.clear();
mUiHelper.detach();
mEngine.destroyRenderer(mRenderer);
mEngine.destroyView(mView);
mEngine.destroyScene(mScene);
mEngine.destroyCameraComponent(mCamera.getEntity());
EntityManager entityManager = EntityManager.get();
entityManager.destroy(mCamera.getEntity());
mEngine.destroy();
}
protected void setupScene() { // 设置Scene参数
}
protected void onResized(int width, int height) { // Surface尺寸变化时回调
double zoom = 1;
double aspect = (double) width / (double) height;
mCamera.setProjection(Camera.Projection.ORTHO,
-aspect * zoom, aspect * zoom, -zoom, zoom, 0, 1000);
}
private void setupSurfaceView() { // 设置SurfaceView
mUiHelper = new UiHelper(UiHelper.ContextErrorPolicy.DONT_CHECK);
mUiHelper.setRenderCallback(new SurfaceCallback());
if (mDesiredSize != null) {
mUiHelper.setDesiredSize(mDesiredSize.x, mDesiredSize.y);
}
mUiHelper.attachTo(this);
}
private void setupFilament() { // 设置Filament参数
mEngine = Engine.create();
// mEngine = (new Engine.Builder()).featureLevel(Engine.FeatureLevel.FEATURE_LEVEL_0).build();
mRenderer = mEngine.createRenderer();
mScene = mEngine.createScene();
mView = mEngine.createView();
mCamera = mEngine.createCamera(mEngine.getEntityManager().create());
}
private void setupView() { // 设置View参数
float[] color = mSkyboxColor != null ? mSkyboxColor : new float[] {0, 0, 0, 1};
Skybox skybox = (new Skybox.Builder()).color(color).build(mEngine);
mScene.setSkybox(skybox);
if (mEngine.getActiveFeatureLevel() == Engine.FeatureLevel.FEATURE_LEVEL_0) {
mView.setPostProcessingEnabled(false); // FEATURE_LEVEL_0不支持post-processing
}
mView.setCamera(mCamera);
mView.setScene(mScene);
}
/*
* 帧回调
*/
private class FrameCallback implements Choreographer.FrameCallback {
@Override
public void doFrame(long frameTimeNanos) { // 渲染每帧数据
if (mRenderMode == RENDERMODE_CONTINUOUSLY) {
mChoreographer.postFrameCallback(this); // 请求下一帧
}
mRenderCallbacks.forEach(callback -> callback.onCall());
if (mUiHelper.isReadyToRender()) {
if (mRenderer.beginFrame(mSwapChain, frameTimeNanos)) {
mRenderer.render(mView);
mRenderer.endFrame();
}
}
}
}
/*
* Surface回调
*/
private class SurfaceCallback implements UiHelper.RendererCallback {
@Override
public void onNativeWindowChanged(Surface surface) { // Native窗口改变时回调
if (mSwapChain != null) {
mEngine.destroySwapChain(mSwapChain);
}
long flags = mUiHelper.getSwapChainFlags();
if (mEngine.getActiveFeatureLevel() == Engine.FeatureLevel.FEATURE_LEVEL_0) {
if (SwapChain.isSRGBSwapChainSupported(mEngine)) {
flags = flags | SwapChain.CONFIG_SRGB_COLORSPACE;
}
}
mSwapChain = mEngine.createSwapChain(surface, flags);
mDisplayHelper.attach(mRenderer, getDisplay());
}
@Override
public void onDetachedFromSurface() { // 解绑Surface时回调
mDisplayHelper.detach();
if (mSwapChain != null) {
mEngine.destroySwapChain(mSwapChain);
mEngine.flushAndWait();
mSwapChain = null;
}
}
@Override
public void onResized(int width, int height) { // Surface尺寸变化时回调
mView.setViewport(new Viewport(0, 0, width, height));
FilamentHelper.synchronizePendingFrames(mEngine);
FLSurfaceView.this.onResized(width, height);
}
}
/*
* 每一帧渲染前的回调
* 一般用于处理模型变换、相机变换等
*/
public static interface RenderCallback {
void onCall();
}
} BaseModel.java
java
package com.zhyan8.multitexture.filament;
import android.content.Context;
import com.google.android.filament.Box;
import com.google.android.filament.Engine;
import com.google.android.filament.EntityManager;
import com.google.android.filament.Material;
import com.google.android.filament.MaterialInstance;
import com.google.android.filament.RenderableManager;
import com.google.android.filament.RenderableManager.PrimitiveType;
import com.google.android.filament.Texture;
import com.google.android.filament.TransformManager;
import com.zhyan8.multitexture.filament.Mesh.SubMesh;
import com.zhyan8.multitexture.filament.utils.MaterialUtils;
import com.zhyan8.multitexture.filament.utils.TextureUtils;
/*
* 模型基类
* 管理模型的网格、材质、渲染id
*/
public class BaseModel {
private static String TAG = "BaseModel";
protected Context mContext; // 上下文
protected Engine mEngine; // Filament引擎
protected TransformManager mTransformManager; // 模型变换管理器
protected Mesh mMesh; // 模型网格
protected SubMesh[] mSubMeshes; // 子网格
protected Material[] mMaterials; // 模型材质
protected MaterialInstance[] mMaterialInstances; // 模型材质实例
protected Texture[] mTextures; // 纹理
protected int mRenderable; // 渲染id
protected int mTransformComponent; // 模型变换组件的id
protected Box mBox; // 渲染区域
protected FLSurfaceView.RenderCallback mRenderCallback; // 每一帧渲染前的回调(一般用于处理模型变换、相机变换等)
public BaseModel(Context context, Engine engine) {
mContext = context;
mEngine = engine;
mTransformManager = mEngine.getTransformManager();
}
public int getRenderable() { // 获取渲染id
return mRenderable;
}
public FLSurfaceView.RenderCallback getRenderCallback() { // 获取渲染回调
return mRenderCallback;
}
public void destroy() { // 销毁模型
mEngine.destroyEntity(mRenderable);
if (mMesh != null) {
mMesh.destroy();
}
if (mTextures != null) {
for (int i = 0; i < mTextures.length; i++) {
mEngine.destroyTexture(mTextures[i]);
}
}
if (mMaterialInstances != null) {
for (int i = 0; i < mMaterialInstances.length; i++) {
mEngine.destroyMaterialInstance(mMaterialInstances[i]);
}
}
if (mMaterials != null) {
for (int i = 0; i < mMaterials.length; i++) {
mEngine.destroyMaterial(mMaterials[i]);
}
}
EntityManager entityManager = EntityManager.get();
entityManager.destroy(mRenderable);
}
protected int getRenderable(PrimitiveType primitiveType, int vertexCount) { // 获取渲染id
int renderable = EntityManager.get().create();
if (mSubMeshes == null) {
mSubMeshes = new SubMesh[] {new SubMesh(0, 0, vertexCount - 1, vertexCount)};
}
RenderableManager.Builder builder = new RenderableManager.Builder(mSubMeshes.length).boundingBox(mBox);
for (int i = 0; i < mSubMeshes.length; i++) {
builder.geometry(i, primitiveType, mMesh.getVertexBuffer(), mMesh.getIndexBuffer(),
mSubMeshes[i].offset, mSubMeshes[i].minIndex, mSubMeshes[i].maxIndex, mSubMeshes[i].indexCount)
.material(i, mMaterialInstances[i]);
}
builder.build(mEngine, renderable);
return renderable;
}
protected Material[] loadMaterials(String materialPath) { // 加载材质
Material material = MaterialUtils.loadMaterial(mContext, mEngine, materialPath);
if (material != null) {
return new Material[] {material};
}
return null;
}
protected Material[] loadMaterials(String[] materialPaths) { // 加载材质
Material[] materials = new Material[materialPaths.length];
for (int i = 0; i < materials.length; i++) {
materials[i] = MaterialUtils.loadMaterial(mContext, mEngine, materialPaths[i]);
}
return materials;
}
protected MaterialInstance[] getMaterialInstance(Material[] materials) { // 获取材质实例
MaterialInstance[] materialInstances = new MaterialInstance[materials.length];
for (int i = 0; i < materials.length; i++) {
materialInstances[i] = materials[i].createInstance();
}
return materialInstances;
}
protected MaterialInstance[] getMaterialInstance(Material material, int count) { // 获取材质实例
MaterialInstance[] materialInstances = new MaterialInstance[count];
for (int i = 0; i < count; i++) {
materialInstances[i] = material.createInstance();
}
return materialInstances;
}
protected Texture[] loadTextures(String texturePath) { // 加载纹理
Texture texture = TextureUtils.getTexture(mContext, mEngine, texturePath);
if (texture != null) {
return new Texture[] {texture};
}
return null;
}
protected Texture[] loadTextures(String[] texturePaths) { // 加载纹理
Texture[] textures = new Texture[texturePaths.length];
for (int i = 0; i < textures.length; i++) {
textures[i] = TextureUtils.getTexture(mContext, mEngine, texturePaths[i]);
}
return textures;
}
} Mesh.java
java
package com.zhyan8.multitexture.filament;
import com.google.android.filament.Engine;
import com.google.android.filament.IndexBuffer;
import com.google.android.filament.VertexBuffer;
import com.google.android.filament.VertexBuffer.AttributeType;
import com.google.android.filament.VertexBuffer.VertexAttribute;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
/*
* 网格
* 用于管理模型的顶点属性和顶点索引
*/
public class Mesh {
private Engine mEngine; // Filament引擎
private VertexBuffer mVertexBuffer; // 顶点属性缓存
private IndexBuffer mIndexBuffer; // 顶点索引缓存
public Mesh(Engine engine) {
mEngine = engine;
}
public Mesh(Engine engine, float[] vertices, short[] indices) {
mEngine = engine;
setVertices(vertices);
setIndices(indices);
}
public Mesh(Engine engine, VertexPosCol[] vertices, short[] indices) {
mEngine = engine;
setVertices(vertices);
setIndices(indices);
}
public Mesh(Engine engine, VertexPosUV[] vertices, short[] indices) {
mEngine = engine;
setVertices(vertices);
setIndices(indices);
}
public void setVertices(float[] vertices) { // 设置顶点属性
mVertexBuffer = getVertexBuffer(vertices);
}
public void setVertices(VertexPosCol[] vertices) { // 设置顶点属性
mVertexBuffer = getVertexBuffer(vertices);
}
public void setVertices(VertexPosUV[] vertices) { // 设置顶点属性
mVertexBuffer = getVertexBuffer(vertices);
}
public void setIndices(short[] indices) { // 设置顶点索引
mIndexBuffer = getIndexBuffer(indices);
}
public VertexBuffer getVertexBuffer() { // 获取顶点属性缓存
return mVertexBuffer;
}
public IndexBuffer getIndexBuffer() { // 获取顶点索引缓存
return mIndexBuffer;
}
public void destroy() {
mEngine.destroyVertexBuffer(mVertexBuffer);
mEngine.destroyIndexBuffer(mIndexBuffer);
}
private VertexBuffer getVertexBuffer(float[] values) { // 获取顶点属性缓存
ByteBuffer vertexData = getByteBuffer(values);
int vertexCount = values.length / 3;
int vertexSize = Float.BYTES * 3;
VertexBuffer vertexBuffer = new VertexBuffer.Builder()
.bufferCount(1)
.vertexCount(vertexCount)
.attribute(VertexBuffer.VertexAttribute.POSITION, 0, VertexBuffer.AttributeType.FLOAT3, 0, vertexSize)
.build(mEngine);
vertexBuffer.setBufferAt(mEngine, 0, vertexData);
return vertexBuffer;
}
private VertexBuffer getVertexBuffer(VertexPosCol[] values) { // 获取顶点属性缓存
ByteBuffer vertexData = getByteBuffer(values);
int vertexCount = values.length;
int vertexSize = VertexPosCol.BYTES;
VertexBuffer vertexBuffer = new VertexBuffer.Builder()
.bufferCount(1)
.vertexCount(vertexCount)
.attribute(VertexAttribute.POSITION, 0, AttributeType.FLOAT3, 0, vertexSize)
.attribute(VertexAttribute.COLOR, 0, AttributeType.UBYTE4, 3 * Float.BYTES, vertexSize)
.normalized(VertexBuffer.VertexAttribute.COLOR)
.build(mEngine);
vertexBuffer.setBufferAt(mEngine, 0, vertexData);
return vertexBuffer;
}
private VertexBuffer getVertexBuffer(VertexPosUV[] values) { // 获取顶点属性缓存
ByteBuffer vertexData = getByteBuffer(values);
int vertexCount = values.length;
int vertexSize = VertexPosUV.BYTES;
VertexBuffer vertexBuffer = new VertexBuffer.Builder()
.bufferCount(1)
.vertexCount(vertexCount)
.attribute(VertexBuffer.VertexAttribute.POSITION, 0, VertexBuffer.AttributeType.FLOAT3, 0, vertexSize)
.attribute(VertexBuffer.VertexAttribute.UV0, 0, VertexBuffer.AttributeType.FLOAT2, 3 * Float.BYTES, vertexSize)
.build(mEngine);
vertexBuffer.setBufferAt(mEngine, 0, vertexData);
return vertexBuffer;
}
private IndexBuffer getIndexBuffer(short[] values) { // 获取顶点索引缓存
ByteBuffer indexData = getByteBuffer(values);
int indexCount = values.length;
IndexBuffer indexBuffer = new IndexBuffer.Builder()
.indexCount(indexCount)
.bufferType(IndexBuffer.Builder.IndexType.USHORT)
.build(mEngine);
indexBuffer.setBuffer(mEngine, indexData);
return indexBuffer;
}
private ByteBuffer getByteBuffer(float[] values) { // float数组转换为ByteBuffer
ByteBuffer byteBuffer = ByteBuffer.allocate(values.length * Float.BYTES);
byteBuffer.order(ByteOrder.nativeOrder());
for (int i = 0; i < values.length; i++) {
byteBuffer.putFloat(values[i]);
}
byteBuffer.flip();
return byteBuffer;
}
private ByteBuffer getByteBuffer(short[] values) { // short数组转换为ByteBuffer
ByteBuffer byteBuffer = ByteBuffer.allocate(values.length * Short.BYTES);
byteBuffer.order(ByteOrder.nativeOrder());
for (int i = 0; i < values.length; i++) {
byteBuffer.putShort(values[i]);
}
byteBuffer.flip();
return byteBuffer;
}
private ByteBuffer getByteBuffer(VertexPosCol[] values) { // VertexPosCol数组转换为ByteBuffer
ByteBuffer byteBuffer = ByteBuffer.allocate(values.length * VertexPosCol.BYTES);
byteBuffer.order(ByteOrder.nativeOrder());
for (int i = 0; i < values.length; i++) {
values[i].put(byteBuffer);
}
byteBuffer.flip();
return byteBuffer;
}
private ByteBuffer getByteBuffer(VertexPosUV[] values) { // VertexPosUV数组转换为ByteBuffer
ByteBuffer byteBuffer = ByteBuffer.allocate(values.length * VertexPosUV.BYTES);
byteBuffer.order(ByteOrder.nativeOrder());
for (int i = 0; i < values.length; i++) {
values[i].put(byteBuffer);
}
byteBuffer.flip();
return byteBuffer;
}
/*
* 子网格
*/
public static class SubMesh {
public int offset;
public int minIndex;
public int maxIndex;
public int indexCount;
public SubMesh() {}
public SubMesh(int offset, int minIndex, int maxIndex, int indexCount) {
this.offset = offset;
this.minIndex = minIndex;
this.maxIndex = maxIndex;
this.indexCount = indexCount;
}
}
/*
* 顶点数据(位置+颜色)
* 包含顶点位置和颜色
*/
public static class VertexPosCol {
public static int BYTES = 16;
public float x;
public float y;
public float z;
public int color;
public VertexPosCol() {}
public VertexPosCol(float x, float y, float z, int color) {
this.x = x;
this.y = y;
this.z = z;
this.color = color;
}
public ByteBuffer put(ByteBuffer buffer) { // VertexPosCol转换为ByteBuffer
buffer.putFloat(x);
buffer.putFloat(y);
buffer.putFloat(z);
buffer.putInt(color);
return buffer;
}
}
/*
* 顶点数据(位置+纹理坐标)
* 包含顶点位置和纹理坐标
*/
public static class VertexPosUV {
public static int BYTES = 20;
public float x;
public float y;
public float z;
public float u;
public float v;
public VertexPosUV() {}
public VertexPosUV(float x, float y, float z, float u, float v) {
this.x = x;
this.y = y;
this.z = z;
this.u = u;
this.v = v;
}
public ByteBuffer put(ByteBuffer buffer) { // VertexPosUV转换为ByteBuffer
buffer.putFloat(x);
buffer.putFloat(y);
buffer.putFloat(z);
buffer.putFloat(u);
buffer.putFloat(v);
return buffer;
}
}
} MaterialUtils.java
java
package com.zhyan8.multitexture.filament.utils;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.os.Handler;
import android.os.Looper;
import android.util.Log;
import com.google.android.filament.Engine;
import com.google.android.filament.Material;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
/*
* 材质工具类
*/
public class MaterialUtils {
private static String TAG = "MaterialUtils";
public static Material loadMaterial(Context context, Engine engine, String materialPath) { // 加载材质
Buffer buffer = readUncompressedAsset(context, materialPath);
if (buffer != null) {
Material material = (new Material.Builder()).payload(buffer, buffer.remaining()).build(engine);
material.compile(
Material.CompilerPriorityQueue.HIGH,
Material.UserVariantFilterBit.ALL,
new Handler(Looper.getMainLooper()),
() -> Log.i(TAG, "Material " + material.getName() + " compiled."));
engine.flush();
return material;
}
return null;
}
private static Buffer readUncompressedAsset(Context context, String assetPath) { // 加载资源
ByteBuffer dist = null;
try {
AssetFileDescriptor fd = context.getAssets().openFd(assetPath);
try(FileInputStream fis = fd.createInputStream()) {
dist = ByteBuffer.allocate((int) fd.getLength());
try (ReadableByteChannel src = Channels.newChannel(fis)) {
src.read(dist);
}
}
} catch (IOException e) {
e.printStackTrace();
}
if (dist != null) {
return dist.rewind();
}
return null;
}
} TextureUtils.java
java
package com.zhyan8.multitexture.filament.utils;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.util.Log;
import com.google.android.filament.Engine;
import com.google.android.filament.Texture;
import com.google.android.filament.android.TextureHelper;
import java.io.IOException;
import java.io.InputStream;
/*
* 纹理工具类
*/
public class TextureUtils {
private static String TAG = "TextureUtils";
public static Texture getTexture(Context context, Engine engine, String texturePath) { // 获取Texture
Bitmap bitmap = loadBitmapFromAsset(context, texturePath);
if (bitmap != null) {
return generateTexture(engine, bitmap);
}
return null;
}
public static Texture getTexture(Context context, Engine engine, int resourceId) { // 获取Texture
Bitmap bitmap = loadBitmapFromDrawable(context, resourceId);
if (bitmap != null) {
return generateTexture(engine, bitmap);
}
return null;
}
private static Texture generateTexture(Engine engine, Bitmap bitmap) { // 生成Texture
Texture texture = new Texture.Builder()
.width(bitmap.getWidth())
.height(bitmap.getHeight())
.sampler(Texture.Sampler.SAMPLER_2D)
.format(Texture.InternalFormat.SRGB8_A8)
.levels(0xff)
.build(engine);
TextureHelper.setBitmap(engine, texture, 0, bitmap, new Handler(), () ->
Log.i(TAG, "getTexture, Bitmap is released.")
);
texture.generateMipmaps(engine);
return texture;
}
private static Bitmap loadBitmapFromAsset(Context context, String assetPath) { // 从asset中加载bitmap
Bitmap bitmap = null;
try (InputStream inputStream = context.getAssets().open(assetPath)) {
bitmap = BitmapFactory.decodeStream(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
private static Bitmap loadBitmapFromDrawable(Context context, int resourceId) { // 从drawable中加载bitmap
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPremultiplied = true;
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);
return bitmap;
}
}2.2 业务类
MainActivity.java
java
package com.zhyan8.multitexture;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import com.zhyan8.multitexture.filament.FLSurfaceView;
public class MainActivity extends AppCompatActivity {
private FLSurfaceView mFLSurfaceView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mFLSurfaceView = new MyFLSurfaceView(this);
setContentView(mFLSurfaceView);
mFLSurfaceView.init();
mFLSurfaceView.setRenderMode(FLSurfaceView.RENDERMODE_CONTINUOUSLY);
}
@Override
public void onResume() {
super.onResume();
mFLSurfaceView.onResume();
}
@Override
public void onPause() {
super.onPause();
mFLSurfaceView.onPause();
}
@Override
public void onDestroy() {
super.onDestroy();
mFLSurfaceView.onDestroy();
}
} MyFLSurfaceView.java
java
package com.zhyan8.multitexture;
import android.content.Context;
import com.google.android.filament.Camera;
import com.zhyan8.multitexture.filament.BaseModel;
import com.zhyan8.multitexture.filament.FLSurfaceView;
public class MyFLSurfaceView extends FLSurfaceView {
private BaseModel mMyModel;
public MyFLSurfaceView(Context context) {
super(context);
}
public void init() {
mSkyboxColor = new float[] {0.35f, 0.35f, 0.35f, 1};
super.init();
}
@Override
public void onDestroy() {
mMyModel.destroy();
super.onDestroy();
}
@Override
protected void setupScene() { // 设置Scene参数
mMyModel = new Cube(getContext(), mEngine);
mScene.addEntity(mMyModel.getRenderable());
addRenderCallback(mMyModel.getRenderCallback());
}
@Override
protected void onResized(int width, int height) {
double zoom = 0.25;
double aspect = (double) width / (double) height;
mCamera.setProjection(Camera.Projection.PERSPECTIVE,
-aspect * zoom, aspect * zoom, -zoom, zoom, 0.3, 100);
float[] eye = new float[] {1, 1, 1.5f};
float[] center = new float[] {0, 0, 0};
float[] up = new float[] {0, 1, 0};
mCamera.lookAt(eye[0], eye[1], eye[2],center[0], center[1], center[2], up[0], up[1], up[2]);
}
} Cube.java
java
package com.zhyan8.multitexture;
import android.content.Context;
import android.opengl.Matrix;
import com.google.android.filament.Box;
import com.google.android.filament.Engine;
import com.google.android.filament.RenderableManager.PrimitiveType;
import com.google.android.filament.TextureSampler;
import com.zhyan8.multitexture.filament.BaseModel;
import com.zhyan8.multitexture.filament.Mesh;
import com.zhyan8.multitexture.filament.Mesh.SubMesh;
import com.zhyan8.multitexture.filament.Mesh.VertexPosUV;
public class Cube extends BaseModel {
private String materialPaths = "materials/square.filamat";
private String[] texturePaths = new String[] {
"textures/a1.jpg", "textures/a2.jpg", "textures/a3.jpg",
"textures/a4.jpg", "textures/a6.jpg", "textures/a5.jpg"
};
private VertexPosUV[] mVertices; // 顶点坐标
private short[] mIndices; // 顶点索引
private float[] mModelMatrix; // 模型变换矩阵
private float[] mRotateAxis; // 旋转轴
private float mRotateAgree = 0; // 旋转角度
public Cube(Context context, Engine engine) {
super(context, engine);
init();
}
private void init() {
mBox = new Box(0.0f, 0.0f, 0.0f, 2.0f, 2.0f, 2.0f);
mVertices = getVertices(0.5f);
mIndices = getIndices();
mMesh = new Mesh(mEngine, mVertices, mIndices);
mSubMeshes = getSubMesh();
mTextures = loadTextures(texturePaths);
mMaterials = loadMaterials(materialPaths);
mMaterialInstances = getMaterialInstance(mMaterials[0], mTextures.length);
TextureSampler textureSampler = new TextureSampler();
for (int i = 0; i < mMaterialInstances.length; i++) {
mMaterialInstances[i].setParameter("mainTex", mTextures[i], textureSampler);
}
mRenderable = getRenderable(PrimitiveType.TRIANGLES, mIndices.length);
mTransformComponent = mTransformManager.getInstance(mRenderable);
mRenderCallback = () -> renderCallback();
mModelMatrix = new float[16];
mRotateAxis = new float[] { 0.5f, 1f, 1f };
}
private void renderCallback() {
mRotateAgree = (mRotateAgree + 1) % 360;
mRotateAxis[0] = mRotateAgree / 180f - 1;
mRotateAxis[1] = (float) Math.sin(mRotateAgree / 180f * Math.PI * 0.7f);
mRotateAxis[2] = (float) Math.cos(mRotateAgree / 180f * Math.PI * 0.5f);
Matrix.setRotateM(mModelMatrix, 0, mRotateAgree, mRotateAxis[0], mRotateAxis[1], mRotateAxis[2]);
mTransformManager.setTransform(mTransformComponent, mModelMatrix);
}
private VertexPosUV[] getVertices(float r) {
VertexPosUV[] vertices = new VertexPosUV[] {
// 前面
new VertexPosUV(r, r, r, 0f, 1f), // 0
new VertexPosUV(-r, r, r, 1f, 1f), // 1
new VertexPosUV(-r, -r, r, 1f, 0f), // 2
new VertexPosUV(r, -r, r, 0f, 0f), // 3
// 后面
new VertexPosUV(r, r, -r, 0f, 1f), // 4
new VertexPosUV(-r, r, -r, 1f, 1f), // 5
new VertexPosUV(-r, -r, -r, 1f, 0f), // 6
new VertexPosUV(r, -r, -r, 0f, 0f), // 7
// 上面
new VertexPosUV(r, r, r, 0f, 1f), // 8
new VertexPosUV(r, r, -r, 1f, 1f), // 9
new VertexPosUV(-r, r, -r, 1f, 0f), // 10
new VertexPosUV(-r, r, r, 0f, 0f), // 11
// 下面
new VertexPosUV(r, -r, r, 0f, 1f), // 12
new VertexPosUV(r, -r, -r, 1f, 1f), // 13
new VertexPosUV(-r, -r, -r, 1f, 0f), // 14
new VertexPosUV(-r, -r, r, 0f, 0f), // 15
// 右面
new VertexPosUV(r, r, r, 0f, 1f), // 16
new VertexPosUV(r, r, -r, 1f, 1f), // 17
new VertexPosUV(r, -r, -r, 1f, 0f), // 18
new VertexPosUV(r, -r, r, 0f, 0f), // 19
// 左面
new VertexPosUV(-r, r, r, 0f, 1f), // 20
new VertexPosUV(-r, r, -r, 1f, 1f), // 21
new VertexPosUV(-r, -r, -r, 1f, 0f), // 22
new VertexPosUV(-r, -r, r, 0f, 0f) // 23
};
return vertices;
}
private short[] getIndices() {
short[] indices = new short[] {
0, 1, 2, 0, 2, 3, // 前面
4, 6, 5, 4, 7, 6, // 上面
8, 9, 10, 8, 10, 11, // 右面
12, 14, 13, 12, 15, 14, // 后面
16, 18, 17, 16, 19, 18, // 下面
20, 21, 22, 20, 22, 23 // 左面
};
return indices;
}
private SubMesh[] getSubMesh() {
int subMeshCount = 6;
int vertexCount = 6;
SubMesh[] subMeshes = new SubMesh[subMeshCount];
for (int i = 0; i < subMeshCount; i++) {
int offset = i * vertexCount;
int minIndex = offset;
int maxIndex = minIndex + vertexCount - 1;
subMeshes[i] = new SubMesh(offset, minIndex, maxIndex, vertexCount);
}
return subMeshes;
}
} square.mat
cpp
material {
name : square,
shadingModel : unlit, // 禁用所有lighting
// 自定义变量参数
parameters : [
{
type : sampler2d,
name : mainTex
}
],
// 顶点着色器入参MaterialVertexInputs中需要的顶点属性
requires : [
uv0
]
}
fragment {
void material(inout MaterialInputs material) {
prepareMaterial(material); // 在方法返回前必须回调该函数
material.baseColor = texture(materialParams_mainTex, getUV0());
}
} transform.bat
bash
@echo off
setlocal enabledelayedexpansion
set "srcFolder=../src/main/materials"
set "distFolder=../src/main/assets/materials"
for %%f in ("%srcFolder%\*.mat") do (
set "matfile=%%~nf"
matc -p mobile -a opengl -o "!matfile!.filamat" "%%f"
move "!matfile!.filamat" "%distFolder%\!matfile!.filamat"
)
echo Processing complete.
pause 说明：需要将 matc.exe 文件与 transform.bat 文件放在同一个目录下面，matc.exe 源自Filament环境搭建中编译生成的 exe 文件。双击 transform.bat 文件，会自动将 /src/main/materials/ 下面的所有 mat 文件全部转换为 filamat 文件，并移到 /src/main/assets/materials/ 目录下面。
运行效果如下。
说明：本文转自【Filament】立方体贴图（6张图）。