我一直在开发一个立方体程序，它提供了许多具有所需品质的立方体。然而，每当我尝试照亮一个有纹理的立方体时，我的立方体就会变得非常暗。照明与无纹理的立方体配合得很好，所以我相信它做得很好，就像没有照明的简单纹理立方体一样。似乎没有关于如何在 OpenGL 2.0+ 中解决此问题的重要文档，但有一些与旧版本有关的内容。
以下link提供了有关为什么我的立方体表现如此的信息，但我在将解决方案转换为较新版本时遇到了麻烦，特别是在我的着色器代码中，我不确定是否应该进行进一步的更改。我正在使用 Android Studio 2.1.3，如果它及其包含的模拟器会对预期效果造成问题。如果有人可以提供任何建议，我将不胜感激。我有一个单独的(大型)渲染器，需要绘制立方体，请告诉我除了我的立方体之外，该代码是否也有用。下面是我的立方体:
public class TexturedLightCube {
/** Cube vertices */
private static final float VERTICES[] = {
-0.3f, -0.3f, -0.3f, //top front right
0.3f, -0.3f, -0.3f, //bottom front right
0.3f, 0.3f, -0.3f, //bottom front left
-0.3f, 0.3f, -0.3f, //top front left
-0.3f, -0.3f, 0.3f, //top back right
0.3f, -0.3f, 0.3f, //bottom back right
0.3f, 0.3f, 0.3f, //bottom back left
-0.3f, 0.3f, 0.3f // top back left
};
/** Vertex colors. */
private static final float COLORS[] = {
0.0f, 1.0f, 1.0f, 1.0f,
1.0f, 0.0f, 0.0f, 1.0f,
1.0f, 1.0f, 0.0f, 1.0f,
0.0f, 1.0f, 0.0f, 1.0f,
0.0f, 0.0f, 1.0f, 1.0f,
1.0f, 0.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f, 1.0f,
0.0f, 1.0f, 1.0f, 1.0f,
};
/** Order to draw vertices as triangles. */
private static final byte INDICES[] = {
0, 1, 3, 3, 1, 2, // Front face.
0, 1, 4, 4, 5, 1, // Bottom face.
1, 2, 5, 5, 6, 2, // Right face.
2, 3, 6, 6, 7, 3, // Top face.
3, 7, 4, 4, 3, 0, // Left face.
4, 5, 7, 7, 6, 5, // Rear face.
};
private static final float TEXTURECOORDS[] =
{
0.0f, 1.0f, //left-bottom
0.0f, 0.0f, //right bottom
1.0f, 0.0f, //left top
1.0f, 1.0f, //right top
0.0f, 1.0f, //left-bottom
0.0f, 0.0f, //right bottom
1.0f, 0.0f, //left top
1.0f, 1.0f, //right top
};
private static final float NORMALS[] = {
//set all normals to all light for testing
1.0f, 1.0f, 1.0f, //top front right
1.0f, 0.0f, 1.0f, //bottom front right
0.0f, 0.0f, 1.0f, //bottom front left
0.0f, 1.0f, 1.0f, //top front left
1.0f, 1.0f, 0.0f, //top back right
1.0f, 0.0f, 0.0f, //bottom back right
0.0f, 0.0f, 0.0f, //bottom back left
0.0f, 1.0f, 0.0f //top back left
};
static final int COORDS_PER_VERTEX = 3;
private static final int VALUES_PER_COLOR = 4;
/** Vertex size in bytes. */
final int VERTEX_STRIDE = COORDS_PER_VERTEX * 4;
/** Color size in bytes. */
private final int COLOR_STRIDE = VALUES_PER_COLOR * 4;
/** Shader code for the vertex. */
private static final String VERTEX_SHADER_CODE =
"uniform mat4 uMVPMatrix;" +
"uniform mat4 uMVMatrix;" +
"uniform vec3 u_LightPos;" +
"attribute vec4 vPosition;" +
"attribute vec4 a_Color;" +
"attribute vec3 a_Normal;" +
"varying vec4 v_Color;" +
"attribute vec2 a_TexCoordinate;" +
"varying vec2 v_TexCoordinate;" +
"void main() {" +
"vec3 modelViewVertex = vec3(uMVMatrix * vPosition);"+
"vec3 modelViewNormal = vec3(uMVMatrix * vec4(a_Normal, 0.0));" +
"float distance = length(u_LightPos - modelViewVertex);" +
"vec3 lightVector = normalize(u_LightPos - modelViewVertex);" +
"float diffuse = max(dot(modelViewNormal, lightVector), 0.1);" +
"diffuse = diffuse * (1.0/(1.0 + (0.00000000000002 * distance * distance)));" + //attenuation factor
"v_Color = a_Color * a_Color * diffuse;" +
"gl_Position = uMVPMatrix * vPosition;" +
"v_TexCoordinate = a_TexCoordinate;" +
"}";
/** Shader code for the fragment. */
private static final String FRAGMENT_SHADER_CODE =
"precision mediump float;" +
"varying vec4 v_Color;" +
"uniform sampler2D u_Texture;"+ //The input texture
"varying vec2 v_TexCoordinate;" +
"void main() {" +
" gl_FragColor = v_Color * texture2D(u_Texture, v_TexCoordinate) ;" + //still works with just color
"}";
private int mTextureUniformHandle; //Pass in texture.
private int mTextureCoordinateHandle; //Pass in model texture coordinate information.
private final int mTextureCoordinateDataSize = 2; //Size of texture coordinate data in elements
public static int mTextureDataHandle; //Handle to texturedata;
private final FloatBuffer mTextureBuffer; //Store model data in float buffer.
private final FloatBuffer mVertexBuffer;
private final FloatBuffer mColorBuffer;
private final FloatBuffer mNormalBuffer;
private final ByteBuffer mIndexBuffer;
private final int mProgram;
private final int mPositionHandle;
private final int mColorHandle;
private final int mMVPMatrixHandle;
private final int mNormalHandle;
public static int mLightPosHandle;
public final int mMVMatrixHandle;
public static int loadTexture(final Context context, final int resourceId) {
//Get the texture from the Android resource directory
final int[] textureHandle = new int[1];
InputStream is = context.getResources().openRawResource(+ R.drawable.teneighty);
Bitmap bitmap = null;
try {
//BitmapFactory is an Android graphics utility for images
bitmap = BitmapFactory.decodeStream(is);
} finally {
//Always clear and close
try {
is.close();
is = null;
} catch (IOException e) {
}
}
//Generate one texture pointer...
GLES20.glGenTextures(1, textureHandle, 0);
//and bind it to our array.
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);
//Create Nearest Filtered Texture.
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
//Accounting for different texture parameters.
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_REPEAT);
GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_REPEAT);
//Use the Android GLUtils to specify a two-dimensional texture image from our bitmap.
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
//Clean up
bitmap.recycle();
if (textureHandle[0] == 0)
{
throw new RuntimeException("Error loading texture");
}
return textureHandle[0];
}
public TexturedLightCube() {
ByteBuffer byteBuffer = ByteBuffer.allocateDirect(VERTICES.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
mVertexBuffer = byteBuffer.asFloatBuffer();
mVertexBuffer.put(VERTICES);
mVertexBuffer.position(0);
byteBuffer = ByteBuffer.allocateDirect(COLORS.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
mColorBuffer = byteBuffer.asFloatBuffer();
mColorBuffer.put(COLORS);
mColorBuffer.position(0);
byteBuffer = ByteBuffer.allocateDirect(NORMALS.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
mNormalBuffer = byteBuffer.asFloatBuffer();
mNormalBuffer.put(NORMALS);
mNormalBuffer.position(0);
byteBuffer = ByteBuffer.allocateDirect(TEXTURECOORDS.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
mTextureBuffer = byteBuffer.asFloatBuffer();
mTextureBuffer.put(TEXTURECOORDS);
mTextureBuffer.position(0);
mIndexBuffer = ByteBuffer.allocateDirect(INDICES.length);
mIndexBuffer.put(INDICES);
mIndexBuffer.position(0);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, loadShader(GLES20.GL_VERTEX_SHADER, VERTEX_SHADER_CODE));
GLES20.glAttachShader(mProgram, loadShader(GLES20.GL_FRAGMENT_SHADER, FRAGMENT_SHADER_CODE));
GLES20.glLinkProgram(mProgram);
mTextureDataHandle = GLES20.glGetUniformLocation(mProgram, "u_Texture");
mTextureCoordinateHandle = GLES20.glGetAttribLocation(mProgram, "a_TexCoordinate");
mTextureUniformHandle = GLES20.glGetUniformLocation(mProgram, "u_Texture");
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
mMVMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVMatrix");
mLightPosHandle = GLES20.glGetUniformLocation(mProgram, "u_LightPos");
mNormalHandle = GLES20.glGetAttribLocation(mProgram, "a_Normal");
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
mColorHandle = GLES20.glGetAttribLocation(mProgram, "a_Color");
}
/**
* Encapsulates the OpenGL ES instructions for drawing this shape.
*
* @param mvpMatrix The Model View Project matrix in which to draw this shape
*/
public void draw(float[] mvpMatrix) {
// Add program to OpenGL environment.
GLES20.glUseProgram(mProgram);
//set active texture unit to texture unit 0.
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);
// Prepare the cube coordinate data.
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, 3, GLES20.GL_FLOAT, false, VERTEX_STRIDE, mVertexBuffer);
// Prepare the cube color data.
GLES20.glEnableVertexAttribArray(mColorHandle);
GLES20.glVertexAttribPointer(mColorHandle, 4, GLES20.GL_FLOAT, false, COLOR_STRIDE, mColorBuffer);
//Will have the same size as Vertex as we are implementing per vertex lighting
GLES20.glEnableVertexAttribArray(mNormalHandle);
GLES20.glVertexAttribPointer(mNormalHandle, 3, GLES20.GL_FLOAT, false, VERTEX_STRIDE, mNormalBuffer);
// Prepare the cube texture data.
GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);
//Pass texture coordinate information.
GLES20.glVertexAttribPointer(mTextureCoordinateHandle,4, GLES20.GL_FLOAT, false, mTextureCoordinateDataSize, mTextureBuffer);
// Apply the projection and view transformation.
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
GLES20.glUniform3f(LightCube.mLightPosHandle, MyGLRenderer.mLightPosInEyeSpace[0], MyGLRenderer.mLightPosInEyeSpace[1], MyGLRenderer.mLightPosInEyeSpace[2]);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glUniform1i(mTextureUniformHandle, 0);
// Draw the cube.
GLES20.glDrawElements(GLES20.GL_TRIANGLES, INDICES.length, GLES20.GL_UNSIGNED_BYTE, mIndexBuffer); //-removed indices-
// Disable vertex arrays.
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glDisableVertexAttribArray(mTextureCoordinateHandle);
GLES20.glDisableVertexAttribArray(mColorHandle);
GLES20.glDisableVertexAttribArray(mNormalHandle);
}
/** Loads the provided shader in the program. */
private static int loadShader(int type, String shaderCode){
int shader = GLES20.glCreateShader(type);
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
最佳答案
- 您的照明缺少一个环境组件，该组件模拟您在现实生活中获得的二阶(及更高阶)反射，但无法直接进入光栅化器。
- 不确定为什么要在片段着色器中对
a_Color进行平方。这肯定会让事情变得更暗，因为所有值都在 0 和 1 之间；例如0.1^2 == 0.01。 - 请记住，您的点积可能为负，因此您需要消除负漫射分量(例如背向光线的表面上没有光强度)。
关于java - 在 OpenGL 2.0+ 中照亮纹理对象，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39667096/