所有对象的z值都为0.0f。如果我不使用着色器来渲染场景,所有对象都能正常显示。所以我认为这可能是矩阵计算问题?
有人知道我在矩阵设置方面哪里出错了吗?
"matrices"是一个自定义类,包含3个矩阵...
public class MatrixUtils {
/* The different matrices */
private Matrix4f modelMatrix = new Matrix4f();
private Matrix4f viewMatrix = new Matrix4f();
private Matrix4f projectionMatrix = new Matrix4f();
public MatrixUtils(){
loadIdentity(modelMatrix);
}
public void loadIdentity(Matrix4f matrix) {
matrix.load(new float[][] {
new float[] { 1, 0, 0, 0 },
new float[] { 0, 1, 0, 0 },
new float[] { 0, 0, 1, 0 },
new float[] { 0, 0, 0, 1 },
});
}
}
在我的GLEventListener
中,我设置了初始值的矩阵。在reshape
方法中调用,设置投影、模型和视图矩阵。
/* (non-Javadoc)
* @see javax.media.opengl.GLEventListener#reshape(javax.media.opengl.GLAutoDrawable, int, int, int, int)
*/
public void reshape(GLAutoDrawable gLDrawable, int x, int y, int width, int height) {
setupOrtho(width, height, 0.1f, 100.0f);
}
一开始,模型和视图矩阵被设置为单位矩阵。投影使用正交矩阵。
private void setupOrtho(float width, float height, float znear, float zfar) {
matrices.loadIdentity(matrices.getModelMatrix());
matrices.loadIdentity(matrices.getViewMatrix());
matrices.setViewMatrix(
setupViewMatrix(
new Vec3(0.0f, 0.0f, 25.0f),
new Vec3(0.0f, 0.0f, 0.0f),
new Vec3(0.0f, 1.0f, 0.0f)));
matrices.setProjectionMatrix(ortho(0, width, 0, height, znear, zfar));
}
计算正交投影
矩阵..
public Matrix4f ortho(float left, float right, float top, float bottom, float zfar, float znear) {
return new Matrix4f(new float[][] {
new float[] { 2 / (right - left), 0, 0, -((right + left) / (right - left)) },
new float[] { 0, 2 / (top - bottom), 0, -((top + bottom) / (top - bottom)) },
new float[] { 0, 0, -2 / (zfar - znear), -((zfar + znear) / (zfar - znear)) },
new float[] { 0, 0, 0, 1 },
});
}
计算 View
矩阵..
public Matrix4f setupViewMatrix(Vec3 position, Vec3 target, Vec3 up) {
Vec3f f = (new Vec3f(target.sub(position))).normalize();
Vec3f s = (new Vec3f(Vec3.cross(f, up))).normalize();
Vec3f u = (new Vec3f(Vec3.cross(s, f)));
return new Matrix4f(
new float[] {
s.x, s.y, s.z, -Vec3.dot(s, position),
u.x, u.y, u.z, -Vec3.dot(u, position),
-f.x, -f.y, -f.z, Vec3.dot(f, position),
0.0f, 0.0f, 0.0f, 1.0f});
}
然后在我的display()
循环内,我将所有3个矩阵传递到每个对象的draw()
函数中。
public void display(GLAutoDrawable gLDrawable) {
for (CustomObject obj : customObjects.size()){
obj.draw(gl2, matrices, getShaderProgram(), obj.getPosition(), 0.0f);
}
}
这是我的自定义对象设置
vertexBuffer
的方式...int COORDS_PER_VERTEX = 3;
int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex
ShortBuffer drawListBuffer;
short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices
float squareCoordsTemp[] = {
-(getWidth() / 2 * getP2M()), (getHeight() / 2 * getP2M()), 0.0f, // top left
-(getWidth() / 2 * getP2M()), -(getHeight() / 2 * getP2M()), 0.0f, // bottom left
(getWidth() / 2 * getP2M()), -(getHeight() / 2 * getP2M()), 0.0f, // bottom right
(getWidth() / 2 * getP2M()), (getHeight() / 2 * getP2M()), 0.0f }; // top right
squareCoords = squareCoordsTemp;
ByteBuffer bb = ByteBuffer.allocateDirect(squareCoords.length * 4); // # of coordinate values * 4 bytes per float
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(squareCoords);
vertexBuffer.position(0);
// initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(drawOrder.length * 2); // # of coordinate values * 2 bytes per short
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
这是我的
CustomObject
绘制的方式..public void draw(final GL2 gl2, MatrixUtils matrices, int shaderProgram, final Vec3 position, final float bodyAngle){
gl2.glUseProgram(shaderProgram);
// enable alpha
gl2.glEnable(GL.GL_BLEND);
gl2.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
// Set color for drawing
setmColorHandle(gl2.glGetUniformLocation(shaderProgram, "vColor"));
gl2.glUniform4fv(getmColorHandle(), 1, getColorArray(), 0);
// get handle to vertex shader's vPosition member
mPositionHandle = gl2.glGetAttribLocation(shaderProgram, "vPosition");
// Enable a handle to the triangle vertices
gl2.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
gl2.glVertexAttribPointer(
mPositionHandle, COORDS_PER_VERTEX,
GL2.GL_FLOAT, false,
vertexStride, vertexBuffer);
// get handle to shape's transformation matrix
mProj = gl2.glGetUniformLocation(shaderProgram, "mProj");
mView = gl2.glGetUniformLocation(shaderProgram, "mView");
mModel = gl2.glGetUniformLocation(shaderProgram, "mModel");
// Apply the projection and view transformation
// getP2M() == 60.0f .. pixels to meters for box2d
matrices.loadIdentity(matrices.getModelMatrix());
matrices.setModelMatrix(matrices.translate(matrices.getModelMatrix(), new Vec3(position.x * getP2M(), position.y * getP2M(), position.z * getP2M())));
matrices.setModelMatrix(matrices.rotate(matrices.getModelMatrix(), bodyAngle, 0, 0, 1));
gl2.glUniformMatrix4fv(mProj, 1, true, matrices.getProjectionMatrix().getValues(), 0);
gl2.glUniformMatrix4fv(mView, 1, true, matrices.getViewMatrix().getValues(), 0);
gl2.glUniformMatrix4fv(mModel, 1, true, matrices.getModelMatrix().getValues(), 0);
// Draw the square
gl2.glDrawElements(
GL2.GL_TRIANGLES, drawOrder.length,
GL2.GL_UNSIGNED_SHORT, drawListBuffer);
// Disable vertex array
gl2.glDisableVertexAttribArray(mPositionHandle);
gl2.glDisable(GL.GL_BLEND);
gl2.glUseProgram(0);
}
Vertex shader ..
#version 120
attribute vec4 vPosition;
uniform mat4 mProj;
uniform mat4 mView;
uniform mat4 mModel;
void main() {
gl_Position = mProj * mView * mModel * vPosition;
}
fragment shader ..
#version 120
uniform vec4 vColor;
void main() {
gl_FragColor = vColor;
}
Definition of Matrix4f
..
public class Matrix4f {
public float[] values;
public Matrix4f() {
this.values = new float[16];
}
/**
* @param values
*/
public Matrix4f(float[] values) {
this.values = values;
}
/**
* @param values
*/
public Matrix4f(float[][] values) {
load(values);
}
/**
* @param values
*/
public void load(float[][] values) {
this.values = new float[] {
values[0][0], values[0][2], values[0][3], values[0][4],
values[1][0], values[1][5], values[1][6], values[1][7],
values[2][0], values[2][8], values[2][9], values[2][10],
values[3][0], values[3][11], values[3][12], values[3][13]
};
}
/**
* Get the values of matrix
*
* @return values
*/
public float[] getValues() {
return this.values;
}
}
矩阵函数...
public Matrix4f translate(Matrix4f matrix, Vec3 vector) {
Matrix4f transform = new Matrix4f(new float[][] {
new float[] { 1, 0, 0, vector.x },
new float[] { 0, 1, 0, vector.y },
new float[] { 0, 0, 1, vector.z },
new float[] { 0, 0, 0, 1 },
});
return multiply(matrix, transform);
}
public Matrix4f rotate(Matrix4f matrix, float angle, int x, int y, int z) {
Matrix4f transform = new Matrix4f();
float cos = (float) Math.cos(angle);
float sin = (float) Math.sin(angle);
if (z == 1) {
transform.load(new float[][] {
new float[] { cos, -sin, 0, 0 },
new float[] { sin, cos, 0, 0 },
new float[] { 0, 0, 1, 0 },
new float[] { 0, 0, 0, 1 },
});
}
//Add onto the matrix and return the result
return multiply(matrix, transform);
}
public Matrix4f add(Matrix4f matrixA, Matrix4f matrixB) {
Matrix4f matrix = new Matrix4f();
for (int a = 0; a < matrix.values.length; a++){
matrix.values[a] = matrixA.values[a] + matrixB.values[a];
}
return matrix;
}
public Matrix4f multiply(Matrix4f matrixA, Matrix4f matrixB) {
Matrix4f matrix = new Matrix4f(new float[][] {
new float[] {
(matrixA.values[0] * matrixB.values[0]) + (matrixA.values[1] * matrixB.values[4]) + (matrixA.values[2] * matrixB.values[8]) + (matrixA.values[3] * matrixB.values[12]),
(matrixA.values[0] * matrixB.values[1]) + (matrixA.values[1] * matrixB.values[5]) + (matrixA.values[2] * matrixB.values[9]) + (matrixA.values[3] * matrixB.values[13]),
(matrixA.values[0] * matrixB.values[2]) + (matrixA.values[1] * matrixB.values[6]) + (matrixA.values[2] * matrixB.values[10]) + (matrixA.values[3] * matrixB.values[14]),
(matrixA.values[0] * matrixB.values[3]) + (matrixA.values[1] * matrixB.values[7]) + (matrixA.values[2] * matrixB.values[11]) + (matrixA.values[3] * matrixB.values[15])
},
new float[] {
(matrixA.values[4] * matrixB.values[0]) + (matrixA.values[5] * matrixB.values[4]) + (matrixA.values[6] * matrixB.values[8]) + (matrixA.values[7] * matrixB.values[12]),
(matrixA.values[4] * matrixB.values[1]) + (matrixA.values[5] * matrixB.values[5]) + (matrixA.values[6] * matrixB.values[9]) + (matrixA.values[7] * matrixB.values[13]),
(matrixA.values[4] * matrixB.values[2]) + (matrixA.values[5] * matrixB.values[6]) + (matrixA.values[6] * matrixB.values[10]) + (matrixA.values[7] * matrixB.values[14]),
(matrixA.values[4] * matrixB.values[3]) + (matrixA.values[5] * matrixB.values[7]) + (matrixA.values[6] * matrixB.values[11]) + (matrixA.values[7] * matrixB.values[15])
},
new float[] {
(matrixA.values[8] * matrixB.values[0]) + (matrixA.values[9] * matrixB.values[4]) + (matrixA.values[10] * matrixB.values[8]) + (matrixA.values[11] * matrixB.values[12]),
(matrixA.values[8] * matrixB.values[1]) + (matrixA.values[9] * matrixB.values[5]) + (matrixA.values[10] * matrixB.values[9]) + (matrixA.values[11] * matrixB.values[13]),
(matrixA.values[8] * matrixB.values[2]) + (matrixA.values[9] * matrixB.values[6]) + (matrixA.values[10] * matrixB.values[10]) + (matrixA.values[11] * matrixB.values[14]),
(matrixA.values[8] * matrixB.values[3]) + (matrixA.values[9] * matrixB.values[7]) + (matrixA.values[10] * matrixB.values[11]) + (matrixA.values[11] * matrixB.values[15])
},
new float[] {
(matrixA.values[12] * matrixB.values[0]) + (matrixA.values[13] * matrixB.values[4]) + (matrixA.values[14] * matrixB.values[8]) + (matrixA.values[15] * matrixB.values[12]),
(matrixA.values[12] * matrixB.values[1]) + (matrixA.values[13] * matrixB.values[5]) + (matrixA.values[14] * matrixB.values[9]) + (matrixA.values[15] * matrixB.values[13]),
(matrixA.values[12] * matrixB.values[2]) + (matrixA.values[13] * matrixB.values[6]) + (matrixA.values[14] * matrixB.values[10]) + (matrixA.values[15] * matrixB.values[14]),
(matrixA.values[12] * matrixB.values[3]) + (matrixA.values[13] * matrixB.values[7]) + (matrixA.values[14] * matrixB.values[11]) + (matrixA.values[15] * matrixB.values[15])
}
});
return matrix;
}
编辑:
我已将制服设置为转置我的矩阵,但是正方形仍然没有居中。 它们应该在屏幕周围形成一个正方形,而不是像这样显示,并且它们似乎无法正确旋转? ..
编辑:
我已更改旋转和平移函数以乘以矩阵,从而解决了旋转问题。 我的最后一个问题是,我似乎没有看着我的场景中心,或者我的对象没有在我的视野中心绘制。 正方形应该在屏幕边缘形成一个盒子,在屏幕中心形成菱形。
我摆放相机的方式有问题吗? ..
setupOrtho
将视野体积定义为 (0,0) 到 (width,height),因此您可能需要根据getHeight/Width
的值进行位置放大(补偿模型矩阵的缺失)。另一件事是你正方形的z
值为零,而你的观察深度为0.1
到100
。目前我会将其更改为-100
到100
(没有视图矩阵,您无法将相机后移,使正方形处于前面)。 - jozxyqk