Java 在OpenGL ES 2.0中绘制球体
我试图在Android上用openGL ES 2.0绘制一个球体。我已经看了相关的问题，并尝试了他们的一些代码，但我仍然无法让它工作 基于这一点，我想出了下面的代码。但是它没有正确绘制；当使用glDrawArrays渲染工作但结果不正确时，当使用glDrawElements时，我得到一个GLU INVALID_操作错误。我在下面列出了缓冲区的内容 javaJava 在OpenGL ES 2.0中绘制球体,java,android,opengl-es,glsl,opengl-es-2.0,Java,Android,Opengl Es,Glsl,Opengl Es 2.0,我试图在Android上用openGL ES 2.0绘制一个球体。我已经看了相关的问题，并尝试了他们的一些代码，但我仍然无法让它工作 基于这一点，我想出了下面的代码。但是它没有正确绘制；当使用glDrawArrays渲染工作但结果不正确时，当使用glDrawElements时，我得到一个GLU INVALID_操作错误。我在下面列出了缓冲区的内容 java public class Sphere { private int stacks; private int slices;
public class Sphere
{
private int stacks;
private int slices;
private float radius;
//Buffers
private FloatBuffer vertexBuffer;
private FloatBuffer colorBuffer;
private ShortBuffer indexBuffer;
//Buffer sizes in aantal bytes
private int vertexBufferSize;
private int colorBufferSize;
private int indexBufferSize;
private int vertexCount;
private int program;
static final int FLOATS_PER_VERTEX = 3; // Het aantal floats in een vertex (x, y, z)
static final int FLOATS_PER_COLOR = 4; // Het aantal floats in een kleur (r, g, b, a)
static final int SHORTS_PER_INDEX = 2;
static final int BYTES_PER_FLOAT = 4;
static final int BYTES_PER_SHORT = 2;
static final int BYTES_PER_VERTEX = FLOATS_PER_VERTEX * BYTES_PER_FLOAT;
static final int BYTES_PER_COLOR = FLOATS_PER_COLOR * BYTES_PER_FLOAT;
static final int BYTES_PER_INDEX_ENTRY = SHORTS_PER_INDEX * BYTES_PER_SHORT;
// Set color with red, green, blue and alpha (opacity) values
private float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
public Sphere(float radius, int stacks, int slices)
{
this.stacks = stacks;
this.slices = slices;
this.radius = radius;
vertexCount = (stacks+1) * (slices+1);
vertexBufferSize = vertexCount * BYTES_PER_VERTEX;
colorBufferSize = vertexCount * BYTES_PER_COLOR;
indexBufferSize = vertexCount * BYTES_PER_INDEX_ENTRY;
program = GLHelpers.createProgram();
if (program == 0) {
return;
}
GLHelpers.checkGlError("program");
// Setup vertex-array buffer. Vertices in float. A float has 4 bytes.
vertexBuffer = ByteBuffer.allocateDirect(vertexBufferSize).order(ByteOrder.nativeOrder()).asFloatBuffer();
colorBuffer = ByteBuffer.allocateDirect(colorBufferSize).order(ByteOrder.nativeOrder()).asFloatBuffer();
indexBuffer = ByteBuffer.allocateDirect(indexBufferSize).order(ByteOrder.nativeOrder()).asShortBuffer();
generateSphereCoords(radius, stacks, slices);
vertexBuffer.position(0);
colorBuffer.position(0);
indexBuffer.position(0);
}
public void draw(float[] modelViewProjectionMatrix)
{
GLES20.glUseProgram(program);
GLHelpers.checkGlError("useprogram");
int positionHandle = GLES20.glGetAttribLocation(program, "a_Position");
GLES20.glEnableVertexAttribArray(positionHandle);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, BYTES_PER_VERTEX, vertexBuffer);
GLHelpers.checkGlError("pos");
//int colorHandle = GLES20.glGetAttribLocation(program, "a_Color");
//GLES20.glEnableVertexAttribArray(colorHandle);
//GLES20.glVertexAttribPointer(colorHandle, 4, GLES20.GL_FLOAT, false, BYTES_PER_COLOR, colorBuffer);
//GLHelpers.checkGlError("color");
int matrixHandle = GLES20.glGetUniformLocation(program, "u_Matrix");
GLES20.glUniformMatrix4fv(matrixHandle, 1, false, modelViewProjectionMatrix, 0);
/*
* When using glDrawArrays rendering works but the results are not correct, when using glDrawElements I get an GL_INVALID_OPERATION error.
*/
GLES20.glDrawElements(GLES20.GL_TRIANGLE_STRIP, indexBuffer.capacity(), GLES20.GL_SHORT, indexBuffer);
//GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, vertexCount);
GLHelpers.checkGlError("draw");
// Disable vertex array
GLES20.glDisableVertexAttribArray(positionHandle);
//GLES20.glDisableVertexAttribArray(colorHandle);
}
private void generateSphereCoords(float radius, int stacks, int slices)
{
for (int stackNumber = 0; stackNumber <= stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber < slices; ++sliceNumber)
{
float theta = (float) (stackNumber * Math.PI / stacks);
float phi = (float) (sliceNumber * 2 * Math.PI / slices);
float sinTheta = FloatMath.sin(theta);
float sinPhi = FloatMath.sin(phi);
float cosTheta = FloatMath.cos(theta);
float cosPhi = FloatMath.cos(phi);
vertexBuffer.put(new float[]{radius * cosPhi * sinTheta, radius * sinPhi * sinTheta, radius * cosTheta});
}
}
for (int stackNumber = 0; stackNumber < stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber <= slices; ++sliceNumber)
{
indexBuffer.put((short) ((stackNumber * slices) + (sliceNumber % slices)));
indexBuffer.put((short) (((stackNumber + 1) * slices) + (sliceNumber % slices)));
}
}
}
}
在glDrawArrays中使用相同的变量，在我看来，该变量没有精确的顶点数 正如创建球体的工作代码所承诺的：
public static Model3D createSphere(float radius, int stacks, int slices)
{
int vertexCount = (stacks + 1) * (slices + 1);
FloatBuffer vertexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_VERTEX).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer normalBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_NORMAL).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer textureCoordBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TEXTURE_COORD).order(ByteOrder.nativeOrder()).asFloatBuffer();
ShortBuffer indexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TRIANGLE_INDEX).order(ByteOrder.nativeOrder()).asShortBuffer();
for (int stackNumber = 0; stackNumber <= stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber <= slices; ++sliceNumber)
{
float theta = (float) (stackNumber * Math.PI / stacks);
float phi = (float) (sliceNumber * 2 * Math.PI / slices);
float sinTheta = FloatMath.sin(theta);
float sinPhi = FloatMath.sin(phi);
float cosTheta = FloatMath.cos(theta);
float cosPhi = FloatMath.cos(phi);
float nx = cosPhi * sinTheta;
float ny = cosTheta;
float nz = sinPhi * sinTheta;
float x = radius * nx;
float y = radius * ny;
float z = radius * nz;
float u = 1.f - ((float)sliceNumber / (float)slices);
float v = (float)stackNumber / (float)stacks;
normalBuffer.put(nx);
normalBuffer.put(ny);
normalBuffer.put(nz);
vertexBuffer.put(x);
vertexBuffer.put(y);
vertexBuffer.put(z);
textureCoordBuffer.put(u);
textureCoordBuffer.put(v);
}
}
for (int stackNumber = 0; stackNumber < stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber < slices; ++sliceNumber)
{
int second = (sliceNumber * (stacks + 1)) + stackNumber;
int first = second + stacks + 1;
//int first = (stackNumber * slices) + (sliceNumber % slices);
//int second = ((stackNumber + 1) * slices) + (sliceNumber % slices);
indexBuffer.put((short) first);
indexBuffer.put((short) second);
indexBuffer.put((short) (first + 1));
indexBuffer.put((short) second);
indexBuffer.put((short) (second + 1));
indexBuffer.put((short) (first + 1));
}
}
vertexBuffer.rewind();
normalBuffer.rewind();
indexBuffer.rewind();
textureCoordBuffer.rewind();
Model3D sphere = new Model3D().setVertexBuffer(vertexBuffer)
.setNormalBuffer(normalBuffer)
.setIndexBuffer(indexBuffer)
.setTexture(R.drawable.earth)
.setTextureCoordBuffer(textureCoordBuffer)
.setDiffuseLighting(-3f, 2.3f, 2f);
return sphere;
}
正如创建球体的工作代码所承诺的：
public static Model3D createSphere(float radius, int stacks, int slices)
{
int vertexCount = (stacks + 1) * (slices + 1);
FloatBuffer vertexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_VERTEX).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer normalBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_NORMAL).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer textureCoordBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TEXTURE_COORD).order(ByteOrder.nativeOrder()).asFloatBuffer();
ShortBuffer indexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TRIANGLE_INDEX).order(ByteOrder.nativeOrder()).asShortBuffer();
for (int stackNumber = 0; stackNumber <= stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber <= slices; ++sliceNumber)
{
float theta = (float) (stackNumber * Math.PI / stacks);
float phi = (float) (sliceNumber * 2 * Math.PI / slices);
float sinTheta = FloatMath.sin(theta);
float sinPhi = FloatMath.sin(phi);
float cosTheta = FloatMath.cos(theta);
float cosPhi = FloatMath.cos(phi);
float nx = cosPhi * sinTheta;
float ny = cosTheta;
float nz = sinPhi * sinTheta;
float x = radius * nx;
float y = radius * ny;
float z = radius * nz;
float u = 1.f - ((float)sliceNumber / (float)slices);
float v = (float)stackNumber / (float)stacks;
normalBuffer.put(nx);
normalBuffer.put(ny);
normalBuffer.put(nz);
vertexBuffer.put(x);
vertexBuffer.put(y);
vertexBuffer.put(z);
textureCoordBuffer.put(u);
textureCoordBuffer.put(v);
}
}
for (int stackNumber = 0; stackNumber < stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber < slices; ++sliceNumber)
{
int second = (sliceNumber * (stacks + 1)) + stackNumber;
int first = second + stacks + 1;
//int first = (stackNumber * slices) + (sliceNumber % slices);
//int second = ((stackNumber + 1) * slices) + (sliceNumber % slices);
indexBuffer.put((short) first);
indexBuffer.put((short) second);
indexBuffer.put((short) (first + 1));
indexBuffer.put((short) second);
indexBuffer.put((short) (second + 1));
indexBuffer.put((short) (first + 1));
}
}
vertexBuffer.rewind();
normalBuffer.rewind();
indexBuffer.rewind();
textureCoordBuffer.rewind();
Model3D sphere = new Model3D().setVertexBuffer(vertexBuffer)
.setNormalBuffer(normalBuffer)
.setIndexBuffer(indexBuffer)
.setTexture(R.drawable.earth)
.setTextureCoordBuffer(textureCoordBuffer)
.setDiffuseLighting(-3f, 2.3f, 2f);
return sphere;
}
另外，整个球体是用一个三角形扇子画的？我希望电杆有两个，然后是一些条纹。谢谢你的回答，代码很混乱，问题可能会更好。我用更好的代码和更多的细节更新了我的问题。另外，整个球体是用一个三角形扇子画的？我希望电杆有两个，然后是一些条纹。谢谢你的回答，代码很混乱，问题可能会更好。我用更好的代码和更多的细节更新了我的问题。如果你只想要一个平滑的球体，你可以用两个三角形作为冒名顶替者，就像我在中描述的那样。如果你只想要一个平滑的球体，你可以用我在中描述的两个三角形作为冒名顶替者来做。什么是Model3D？什么是Model3D？
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
public static Model3D createSphere(float radius, int stacks, int slices)
{
int vertexCount = (stacks + 1) * (slices + 1);
FloatBuffer vertexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_VERTEX).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer normalBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_NORMAL).order(ByteOrder.nativeOrder()).asFloatBuffer();
FloatBuffer textureCoordBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TEXTURE_COORD).order(ByteOrder.nativeOrder()).asFloatBuffer();
ShortBuffer indexBuffer = ByteBuffer.allocateDirect(vertexCount * GLHelpers.BYTES_PER_TRIANGLE_INDEX).order(ByteOrder.nativeOrder()).asShortBuffer();
for (int stackNumber = 0; stackNumber <= stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber <= slices; ++sliceNumber)
{
float theta = (float) (stackNumber * Math.PI / stacks);
float phi = (float) (sliceNumber * 2 * Math.PI / slices);
float sinTheta = FloatMath.sin(theta);
float sinPhi = FloatMath.sin(phi);
float cosTheta = FloatMath.cos(theta);
float cosPhi = FloatMath.cos(phi);
float nx = cosPhi * sinTheta;
float ny = cosTheta;
float nz = sinPhi * sinTheta;
float x = radius * nx;
float y = radius * ny;
float z = radius * nz;
float u = 1.f - ((float)sliceNumber / (float)slices);
float v = (float)stackNumber / (float)stacks;
normalBuffer.put(nx);
normalBuffer.put(ny);
normalBuffer.put(nz);
vertexBuffer.put(x);
vertexBuffer.put(y);
vertexBuffer.put(z);
textureCoordBuffer.put(u);
textureCoordBuffer.put(v);
}
}
for (int stackNumber = 0; stackNumber < stacks; ++stackNumber)
{
for (int sliceNumber = 0; sliceNumber < slices; ++sliceNumber)
{
int second = (sliceNumber * (stacks + 1)) + stackNumber;
int first = second + stacks + 1;
//int first = (stackNumber * slices) + (sliceNumber % slices);
//int second = ((stackNumber + 1) * slices) + (sliceNumber % slices);
indexBuffer.put((short) first);
indexBuffer.put((short) second);
indexBuffer.put((short) (first + 1));
indexBuffer.put((short) second);
indexBuffer.put((short) (second + 1));
indexBuffer.put((short) (first + 1));
}
}
vertexBuffer.rewind();
normalBuffer.rewind();
indexBuffer.rewind();
textureCoordBuffer.rewind();
Model3D sphere = new Model3D().setVertexBuffer(vertexBuffer)
.setNormalBuffer(normalBuffer)
.setIndexBuffer(indexBuffer)
.setTexture(R.drawable.earth)
.setTextureCoordBuffer(textureCoordBuffer)
.setDiffuseLighting(-3f, 2.3f, 2f);
return sphere;
}