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我创建了一个由 X、Y 和 Z 轴坐标组成的 3-d numpy 数组。现在我正在尝试在 opengl 中使用这些点创建一个曲面,但我所取得的成功只是创建了如下所示的线模型模型。任何人都可以建议更改我的代码以从数据中形成实际的 3-D 表面吗?数据文件使用链接https://drive.google.com/open?id=1PWbNIt3xbchtQ9HIIS96k7ZjblzPO_wO

代码:-

import OpenGL.GL as gl
import OpenGL.arrays.vbo as glvbo
from PyQt5.Qt import *
import numpy as np
import Backend_algo as Sb
import sys
import ctypes


def compile_vertex_shader(source):
    """Compile a vertex shader from source."""
    vertex_shader = gl.glCreateShader(gl.GL_VERTEX_SHADER)
    gl.glShaderSource(vertex_shader, source)
    gl.glCompileShader(vertex_shader)
    # check compilation error
    result = gl.glGetShaderiv(vertex_shader, gl.GL_COMPILE_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetShaderInfoLog(vertex_shader))
    return vertex_shader


def compile_fragment_shader(source):
    """Compile a fragment shader from source."""
    fragment_shader = gl.glCreateShader(gl.GL_FRAGMENT_SHADER)
    gl.glShaderSource(fragment_shader, source)
    gl.glCompileShader(fragment_shader)
    result = gl.glGetShaderiv(fragment_shader, gl.GL_COMPILE_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetShaderInfoLog(fragment_shader))
    return fragment_shader


def link_shader_program(vertex_shader, fragment_shader):
    """Create a shader program with from compiled shaders."""
    program = gl.glCreateProgram()
    gl.glAttachShader(program, vertex_shader)
    gl.glAttachShader(program, fragment_shader)
    gl.glLinkProgram(program)

    result = gl.glGetProgramiv(program, gl.GL_LINK_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetProgramInfoLog(program))
    return program


VS = '''

attribute vec3 position;


uniform float right;
uniform float bottom;
uniform float left;
uniform float top;
uniform float far;
uniform float near;

void main() {

    mat4 testmat = mat4(
            vec4(2.0 / (right - left), 0, 0, 0),
            vec4(0, 2.0 / (top - bottom), 0, 0),
            vec4(0, 0, -2.0 / (far - near), 0),
            vec4(-(right + left) / (right - left), -(top + bottom) / (top - bottom), -(far + near) / (far - near), 1)
    );

    gl_Position = testmat * vec4(position, 1.);

}

'''
FS = '''
#version 450
// Output variable of the fragment shader, which is a 4D vector containing the
// RGBA components of the pixel color.
uniform vec3 triangleColor;
out vec4 outColor;

void main()
{
    outColor = vec4(triangleColor, 1.0);
}
'''


class GLPlotWidget3D(QGLWidget):

    def __init__(self, *args):
        # QGLWidget.__init__(self)
        super(GLPlotWidget3D, self).__init__()
        # self.parent = args[0]
        self.width, self.height = 100, 100
        self.right, self.left, self.top, self.bottom = 21000, -21000, 10, -10
        self.data = np.zeros((3, 10, 2))
        self.vbo = glvbo.VBO(self.data)

        self.showMaximized()

    def initializeGL(self):
        vs = Sb.compile_vertex_shader(VS)
        fs = Sb.compile_fragment_shader(FS)
        self.shaders_program = link_shader_program(vs, fs)
        self.e = np.load(('three.npy'), mmap_mode='r')
        self.e = np.array(self.e, dtype=np.float32)

        self.right, self.left, self.top, self.bottom, self.far, self.near = self.e[:, :, 1].min(), self.e[:, : , 1].max(), self.e[:, : , 0].min(), self.e[:, : , 0].max(), self.e[:, : , 2].max(), self.e[:, : , 2].min()

    def ortho_view(self):
        right = gl.glGetUniformLocation(self.shaders_program, "right")
        gl.glUniform1f(right, self.right)

        left = gl.glGetUniformLocation(self.shaders_program, "left")
        gl.glUniform1f(left, self.left)

        top = gl.glGetUniformLocation(self.shaders_program, "top")
        gl.glUniform1f(top, self.top)

        bottom = gl.glGetUniformLocation(self.shaders_program, "bottom")
        gl.glUniform1f(bottom, self.bottom)

        far = gl.glGetUniformLocation(self.shaders_program, "far")
        gl.glUniform1f(far, self.far)

        near = gl.glGetUniformLocation(self.shaders_program, "near")
        gl.glUniform1f(near, self.near)


    def paintGL(self):
        self.resizeGL(self.width, self.height)
        gl.glClearColor(0.2, 0.2, 0.2, 0)
        gl.glClear(gl.GL_COLOR_BUFFER_BIT)
        gl.glUseProgram(self.shaders_program)

        buffer = gl.glGenBuffers(1)

        gl.glBindBuffer(gl.GL_ARRAY_BUFFER, buffer)
        stride = self.e.strides[0]
        offset = ctypes.c_void_p(1)
        loc = gl.glGetAttribLocation(self.shaders_program, "position")
        gl.glEnableVertexAttribArray(loc)
        gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, stride, offset)
        gl.glBufferData(gl.GL_ARRAY_BUFFER, self.e.nbytes, self.e, gl.GL_DYNAMIC_DRAW)

        gl.glDrawArrays(gl.GL_LINE_LOOP, 0, self.e.shape[0])

        self.ortho_view()
        uni_color = gl.glGetUniformLocation(self.shaders_program, "triangleColor")
        gl.glUniform3f(uni_color, 0.9, 0.9, 0.9)


    def resizeGL(self, width, height):
        self.width, self.height = width, height
        gl.glViewport(0, 0, width, height)


def main():
    app = QApplication(sys.argv)
    editor = GLPlotWidget3D()
    editor.show()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()
4

1 回答 1

1

“three.npy”包含一个 3 维数组 (7782 x 24 x3),其中包含管的顶点坐标。大小为 3 的第 3 维包含顶点的xyz坐标。顶点被组织成 7782 个环,圆周上有 24 个点。

将顶点坐标读取到展平缓冲区(numpy 数组自动展平glBufferData)。
生成索引数组(顶点缓冲区的索引)。索引描述GL_TRIANGLE_STRIP了堆叠 7781 个环的原语。每个环由圆周上的 24 个四边形组成。

self.e = np.load(('three.npy'), mmap_mode='r')
self.e = np.array(self.e, dtype=np.float32)

self.elems = []
ring_c = self.e.shape[1]
slice_c = self.e.shape[0]
for si in range(slice_c-1):
    self.elems += [si*ring_c, si*ring_c]
    for ri in range(ring_c+1):
        ie = ri % ring_c
        self.elems += [ie+si*ring_c, ie+(si+1)*ring_c]
self.elems = np.array(self.elems, dtype=np.int32)

顶点的xy分量在 [-10, 10] 范围内,但 z 分量在 [3, 2972​​4672] 范围内。

x min      x max     y min      y max     z min      z max
-10.589109 10.517833 -10.464569 10.594374 29724672.0 3.1618009

我建议为 z 坐标定义一个比例:

self.scaleZ = 0.000001

为顶点创建一个顶点缓冲区对象( GL_ARRAY_BUFFER),为索引创建一个索引缓冲区对象( GL_ELEMENT_ARRAY_BUFFER):

self.vertexbuffer = gl.glGenBuffers(1)
gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.vertexbuffer)
gl.glBufferData(gl.GL_ARRAY_BUFFER, self.e, gl.GL_DYNAMIC_DRAW)

self.elementbuffer = gl.glGenBuffers(1)
gl.glBindBuffer(gl.GL_ELEMENT_ARRAY_BUFFER, self.elementbuffer)
gl.glBufferData(gl.GL_ELEMENT_ARRAY_BUFFER, self.elems, gl.GL_DYNAMIC_DRAW)

指定顶点坐标数组。请参阅顶点规范。的stride和 offset参数glVertexAttribPointer必须为 0。stride
指定连续通用顶点属性之间的字节偏移量,它必须是3*self.e.itemsize(12) 或0。0 具有特殊含义,并将属性解释为紧密包装。如果stride为 0,则由sizetype参数计算。
offset必须是ctypes.c_void_p(0)or None,因为数组中第 1 个属性的偏移量是 0。
无论如何,strideoffset的单位都是字节。

gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.vertexbuffer)
stride = 0 # 3*self.e.itemsize
offset = None # ctypes.c_void_p(0)
loc = self.attrib['position']
gl.glEnableVertexAttribArray(loc)
gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, stride, offset)

原始类型是并且必须在绘制元素GL_TRIANGLE_STRIP之前绑定索引缓冲区glDrawElements

gl.glBindBuffer(gl.GL_ELEMENT_ARRAY_BUFFER, self.elementbuffer)

self.perspective_view()
gl.glUniform3f(self.uniform['triangleColor'], 1, 1, 1)
gl.glDrawElements(gl.GL_TRIANGLE_STRIP, self.elems.size, gl.GL_UNSIGNED_INT, None)

我建议不要在顶点着色器中指定正交投影矩阵,而是使用矩阵Uniform 变量进行投影,分别是模型和视图变换。
投影矩阵定义了 3 维视域到 2 维视口的投影。视图矩阵定义了视图的查看位置和对场景的查看方向。模型矩阵定义了模式的比例和动画。

attribute vec3 position;

uniform mat4 u_proj;
uniform mat4 u_view;
uniform mat4 u_model;

void main() {

    gl_Position = u_proj * u_view * u_model * vec4(position, 1.0);
}

获取着色器程序链接后的属性索引和统一位置:

vs = compile_vertex_shader(VS)
fs = compile_fragment_shader(FS)
self.shaders_program = link_shader_program(vs, fs)
self.attrib = { a : gl.glGetAttribLocation (self.shaders_program, a) for a in ['position'] }
print(self.attrib)
self.uniform = { u : gl.glGetUniformLocation (self.shaders_program, u) for u in ['u_model', 'u_view', 'u_proj', "triangleColor"] }
print(self.uniform)

对于 3D 外观,我建议使用Perspective projection而不是Orthographic projection
使用numpy.arraynumpy.matrix设置矩阵。

# projection matrix
aspect, ta, near, far = self.width/self.height, np.tan(np.radians(90.0) / 2), 0.1, 50
proj = np.matrix(((1/ta/aspect, 0, 0, 0), (0, 1/ta, 0, 0), (0, 0, -(far+near)/(far-near), -1), (0, 0, -2*far*near/(far-near), 0)), np.float32)

# view matrix
view = np.matrix(((1, 0, 0, 0), (0, 0, -1, 0), (0, 1, 0, 0), (0, 0, -30, 1)), np.float32)

# model matrix
c, s = math.cos(self.angle), math.sin(self.angle)
model = scale

gl.glUniformMatrix4fv(self.uniform['u_proj'], 1, gl.GL_FALSE, proj)
gl.glUniformMatrix4fv(self.uniform['u_view'], 1, gl.GL_FALSE, view)
gl.glUniformMatrix4fv(self.uniform['u_model'], 1, gl.GL_FALSE, model)

完整示例:(
片段着色器根据片段的深度对片段进行着色)

import OpenGL.GL as gl
import OpenGL.arrays.vbo as glvbo
from PyQt5.Qt import *
import numpy as np
#import Backend_algo as Sb
import sys
import ctypes
import os
import math

sourceFileDir = os.path.dirname(os.path.abspath(__file__))

def compile_vertex_shader(source):
    """Compile a vertex shader from source."""
    vertex_shader = gl.glCreateShader(gl.GL_VERTEX_SHADER)
    gl.glShaderSource(vertex_shader, source)
    gl.glCompileShader(vertex_shader)
    # check compilation error
    result = gl.glGetShaderiv(vertex_shader, gl.GL_COMPILE_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetShaderInfoLog(vertex_shader))
    return vertex_shader

def compile_fragment_shader(source):
    """Compile a fragment shader from source."""
    fragment_shader = gl.glCreateShader(gl.GL_FRAGMENT_SHADER)
    gl.glShaderSource(fragment_shader, source)
    gl.glCompileShader(fragment_shader)
    result = gl.glGetShaderiv(fragment_shader, gl.GL_COMPILE_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetShaderInfoLog(fragment_shader))
    return fragment_shader

def link_shader_program(vertex_shader, fragment_shader):
    """Create a shader program with from compiled shaders."""
    program = gl.glCreateProgram()
    gl.glAttachShader(program, vertex_shader)
    gl.glAttachShader(program, fragment_shader)
    gl.glLinkProgram(program)

    result = gl.glGetProgramiv(program, gl.GL_LINK_STATUS)
    if not (result):
        raise RuntimeError(gl.glGetProgramInfoLog(program))
    return program

VS = '''
attribute vec3 position;

uniform mat4 u_proj;
uniform mat4 u_view;
uniform mat4 u_model;

void main() {

    gl_Position = u_proj * u_view * u_model * vec4(position, 1.0);
}
'''

FS = '''
#version 450
out vec4 outColor;

uniform vec3 triangleColor;

void main()
{
    float d = 1.0 - gl_FragCoord.z;
    outColor = vec4(triangleColor * d, 1.0);
}
'''

class GLPlotWidget3D(QGLWidget):

    def __init__(self, *args):
        # QGLWidget.__init__(self)
        super(GLPlotWidget3D, self).__init__()
        # self.parent = args[0]
        self.width, self.height = 100, 100
        self.right, self.left, self.top, self.bottom = 21000, -21000, 10, -10
        self.data = np.zeros((3, 10, 2))
        self.vbo = glvbo.VBO(self.data)

        self.showMaximized()

    def initializeGL(self):

        vs = compile_vertex_shader(VS)
        fs = compile_fragment_shader(FS)
        self.shaders_program = link_shader_program(vs, fs)
        self.attrib = { a : gl.glGetAttribLocation (self.shaders_program, a) for a in ['position'] }
        print(self.attrib)
        self.uniform = { u : gl.glGetUniformLocation (self.shaders_program, u) for u in ['u_model', 'u_view', 'u_proj', "triangleColor"] }
        print(self.uniform)

        self.e = np.load((os.path.join(sourceFileDir,'three.npy')), mmap_mode='r')
        self.e = np.array(self.e, dtype=np.float32)
        print(self.e.shape)

        self.elems = []
        ring_c = self.e.shape[1]
        slice_c = self.e.shape[0]
        for si in range(slice_c-1):
            self.elems += [si*ring_c, si*ring_c]
            for ri in range(ring_c+1):
                ie = ri % ring_c
                self.elems += [ie+si*ring_c, ie+(si+1)*ring_c]

        self.elems = np.array(self.elems, dtype=np.int32)

        self.vertexbuffer = gl.glGenBuffers(1)
        gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.vertexbuffer)
        gl.glBufferData(gl.GL_ARRAY_BUFFER, self.e, gl.GL_DYNAMIC_DRAW)

        self.elementbuffer = gl.glGenBuffers(1)
        gl.glBindBuffer(gl.GL_ELEMENT_ARRAY_BUFFER, self.elementbuffer)
        gl.glBufferData(gl.GL_ELEMENT_ARRAY_BUFFER, self.elems, gl.GL_DYNAMIC_DRAW)

        self.scaleZ = 0.000001
        self.right, self.left, self.top, self.bottom, self.far, self.near = self.e[:, :, 1].min(), self.e[:, : , 1].max(), self.e[:, : , 0].min(), self.e[:, : , 0].max(), self.e[:, : , 2].max(), self.e[:, : , 2].min()
        print(self.right, self.left, self.top, self.bottom, self.far, self.near)
        self.far *= self.scaleZ
        self.near *= self.scaleZ
        self.angle = 0.0

        self.GLtimer = QTimer()
        self.GLtimer.setInterval(10)
        self.GLtimer.timeout.connect(self.redraw)
        self.GLtimer.start()

    def redraw(self):
        self.angle += 0.01
        self.update()

    def perspective_view(self):

        # projection matrix
        aspect, ta, near, far = self.width/self.height, np.tan(np.radians(90.0) / 2), 10, 50
        proj = np.matrix(((1/ta/aspect, 0, 0, 0), (0, 1/ta, 0, 0), (0, 0, -(far+near)/(far-near), -1), (0, 0, -2*far*near/(far-near), 0)), np.float32)

        # view matrix
        view = np.matrix(((1, 0, 0, 0), (0, 0, -1, 0), (0, 1, 0, 0), (0, 0, -30, 1)), np.float32)

        # model matrix
        c, s = math.cos(self.angle), math.sin(self.angle)
        scale = np.matrix(((1, 0, 0, 0), (0, 1, 0, 0), (0, 0, self.scaleZ, 0), (0, 0, 0, 1)), np.float32)
        rotZ = np.array(((c, s, 0, 0), (-s, c, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1)), np.float32) 
        rotY = np.matrix(((0, 0, 1, 0), (0, 1, 0, 0), (-1, 0, 0, 0), (0, 0, 0, 1)), np.float32)
        trans = np.matrix(((1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, (self.near - self.far)/2, 1)), np.float32)
        model = scale * trans * rotY * rotZ

        gl.glUniformMatrix4fv(self.uniform['u_proj'], 1, gl.GL_FALSE, proj)
        gl.glUniformMatrix4fv(self.uniform['u_view'], 1, gl.GL_FALSE, view)
        gl.glUniformMatrix4fv(self.uniform['u_model'], 1, gl.GL_FALSE, model)


    def paintGL(self):
        self.resizeGL(self.width, self.height)
        gl.glClearColor(0.2, 0.2, 0.2, 0)
        gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
        gl.glEnable(gl.GL_DEPTH_TEST)
        gl.glUseProgram(self.shaders_program)

        gl.glBindBuffer(gl.GL_ARRAY_BUFFER, self.vertexbuffer)
        stride = 0 # 3*self.e.itemsize
        offset = None # ctypes.c_void_p(0)
        loc = self.attrib['position']
        gl.glEnableVertexAttribArray(loc)
        gl.glVertexAttribPointer(loc, 3, gl.GL_FLOAT, False, stride, offset)

        gl.glBindBuffer(gl.GL_ELEMENT_ARRAY_BUFFER, self.elementbuffer)

        self.perspective_view()
        gl.glUniform3f(self.uniform['triangleColor'], 1, 1, 1)
        #gl.glPolygonMode(gl.GL_FRONT_AND_BACK, gl.GL_LINE)
        gl.glDrawElements(gl.GL_TRIANGLE_STRIP, self.elems.size, gl.GL_UNSIGNED_INT, None)

    def resizeGL(self, width, height):
        self.width, self.height = width, height
        gl.glViewport(0, 0, width, height)

def main():
    app = QApplication(sys.argv)
    editor = GLPlotWidget3D()
    editor.show()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()
于 2020-01-18T12:01:05.517 回答