PyOpenGL纹理_3D和Numpy未渲染

gorkyyrv  于 2023-01-13  发布在  其他
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我尝试做一个简单的渲染,从TIFF图像加载数据到numpy矩阵,并制作一个3D纹理。TIFF图像是强度图像,我希望将这个强度图像重新Map为亮度或alpha颜色图像。
虽然我认为我理解GL_Texture_3D的过程,但运行代码时没有任何错误,我仍然没有获得任何视觉结果。我肯定是做了一些简单的非常错误的事情。有人能帮助我理解我的错误吗?
这是代码的简短版本[corrected]:

**编辑2:尝试正确的类型转换:**正如Reto Koradi所建议的,我可能面临着一个类型转换问题。所以我将numpy数组转换为uint8,确保值不全为零,并将其传递给channel_RGBA_buffer uint8数组。仍然会产生一个黑色窗口。
**编辑3:使用Glumpy方法:**阅读Glumpy(https://code.google.com/p/glumpy/source/browse/glumpy/image/texture.py?r=8cbc2aa2b277c07b59fba964edd327370a8e8091)的函数“textures”我将目标GL格式GL_RGBA更改为GL_RGBA16,并在调用glTexImage3D后添加了glBindTexture(GL_TEXTURE_3D,0)。仍然不确定为什么是0而不是纹理。
编辑4:修复了2行的缩进,使示例可执行

结果仍然是一个黑色的窗口,但当关闭这个窗口,一瞬间,我看到的数据出现。似乎我把一个额外的层。

import sys

import numpy
from OpenGL.GL import *
from OpenGL.GL.shaders import *
from OpenGL.arrays import vbo
from OpenGL.GLU import *
from OpenGL.GLUT import *
from OpenGL.GLUT.freeglut import *



class test_TIFF_render:

    def __init__(self):
        self.something = True

    def load_texture(self):

        global texture

        #read file as array, for simplicity I will just make a random numpy 3D matrix 
        tiff_mean = numpy.random.rand(3,300,300)
        tiff_mean = tiff_mean*1000
        tiff_mean = tiff_mean.astype('uint8')

        shape_array = tiff_mean.shape
        shape_array = tiff_mean.shape
        #we have the data now, let's set the texture
        tiff_mean = tiff_mean.reshape(tiff_mean.shape[1]*tiff_mean.shape[2]*tiff_mean.shape[0])
        texture = glGenTextures(1)
        glBindTexture(GL_TEXTURE_3D,texture)
        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE)
        glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S,GL_CLAMP_TO_BORDER)
        glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T,GL_CLAMP_TO_BORDER)
        glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R,GL_CLAMP_TO_BORDER)
        glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)

        #now we need to convert the intensity data organized in 3D matrix into an RGBA buffer array (pixel1R, pixel1G, pixel1B, pixel1A, pixel2R....)
        channel_RGBA_buffer = numpy.zeros(tiff_mean.shape[0]*4, numpy.uint8)

        for i in range(0,tiff_mean.shape[0]):
            channel_RGBA_buffer[i*4] = tiff_mean[i]     #R
            channel_RGBA_buffer[i*4+1] = tiff_mean[i]   #G
            channel_RGBA_buffer[i*4+2] = tiff_mean[i]   #B
            channel_RGBA_buffer[i*4+3] = tiff_mean[i]   #A
            if numpy.mod(i,100000)==0:
                print('count %d',i)

        
        glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA16, shape_array[1], shape_array[2], shape_array[0], 0, GL_RGBA, GL_UNSIGNED_BYTE, channel_RGBA_buffer)
        glBindTexture( GL_TEXTURE_3D, 0 )

    def display(self):

        glClear( GL_COLOR_BUFFER_BIT  | GL_DEPTH_BUFFER_BIT )

        glEnable( GL_ALPHA_TEST )
        glAlphaFunc( GL_GREATER, 0.03)

        glEnable(GL_BLEND)
        glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA )

        glMatrixMode( GL_TEXTURE )
        glLoadIdentity()

        

        glEnable(GL_TEXTURE_3D);
        glBindTexture( GL_TEXTURE_3D, texture);
        dOrthoSize = 1
        for Indx in self.my_range(-1,1,0.01):
            TexIndex = round(Indx,2)
            glBegin(GL_QUADS)
            glTexCoord3f(0.0, 0.0, (TexIndex+1.0)/2.0)
            glVertex3f(-dOrthoSize,-dOrthoSize,TexIndex)
            glTexCoord3f(1.0, 0.0, (TexIndex+1.0)/2.0)
            glVertex3f(dOrthoSize,-dOrthoSize,TexIndex)
            glTexCoord3f(1.0, 1.0, (TexIndex+1.0)/2.0)
            glVertex3f(dOrthoSize,dOrthoSize,TexIndex)
            glTexCoord3f(0.0, 1.0, (TexIndex+1.0)/2.0)
            glVertex3f(-dOrthoSize,dOrthoSize,TexIndex);
            glEnd()

        glBindTexture( GL_TEXTURE_3D, texture )

    def my_range(self,start, end, step):
        while start <= end:
            yield start
            start += step

glutInit(sys.argv)
glutInitDisplayMode(GLUT_RGBA)

glutInitWindowSize(300,300)
window = glutCreateWindow(b"I really hope this works")

test111 = test_TIFF_render()
test111.load_texture()

glutDisplayFunc(test111.display)
glutMainLoop()

我运行的是64位Win7和Python3.3。

kjthegm6

kjthegm61#

我没有使用过numpy,但是我读过文档(http://docs.scipy.org/doc/numpy/reference/generated/numpy.zeros.html),默认情况下numpy.zeros()生成一个float64值的数组,然后将GL_INT作为glTexImage3D()的类型参数传递,看起来这里有一个类型不匹配。
用于纹理数据的典型数据类型是unsigned bytes。所以我认为它应该看起来像这样:

channel_RGBA_buffer = numpy.zeros(tiff_mean.shape[0]*4, numpy.uint8)
...
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, shape_array[1], shape_array[2], shape_array[0], 0,
             GL_RGBA, GL_UNSIGNED_BYTE, channel_RGBA_buffer)

编辑,更新新版本代码:它看起来像是生成0.0到1.0之间的随机浮点值,并将它们转换为字节(uint8)值,然后将其用于纹理数据。我相信这将导致所有字节值为0,或者可能部分为1,这取决于舍入的工作方式。但是字节范围的值是0-255。您可能希望乘以255。将随机浮点转换为纹理数据时为0:

channel_RGBA_buffer[i*4] = 255.0 * tiff_mean[i]     #R
channel_RGBA_buffer[i*4+1] = 255.0 * tiff_mean[i]   #G
channel_RGBA_buffer[i*4+2] = 255.0 * tiff_mean[i]   #B
channel_RGBA_buffer[i*4+3] = 255.0 * tiff_mean[i]   #A

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