Source code for pyqtgraph.opengl.items.GLVolumeItem

# -*- coding: utf-8 -*-
from OpenGL.GL import *
from .. GLGraphicsItem import GLGraphicsItem
from ...Qt import QtGui
import numpy as np

__all__ = ['GLVolumeItem']

[docs]class GLVolumeItem(GLGraphicsItem): """ **Bases:** :class:`GLGraphicsItem <pyqtgraph.opengl.GLGraphicsItem>` Displays volumetric data. """
[docs] def __init__(self, data, sliceDensity=1, smooth=True, glOptions='translucent'): """ ============== ======================================================================================= **Arguments:** data Volume data to be rendered. *Must* be 4D numpy array (x, y, z, RGBA) with dtype=ubyte. sliceDensity Density of slices to render through the volume. A value of 1 means one slice per voxel. smooth (bool) If True, the volume slices are rendered with linear interpolation ============== ======================================================================================= """ self.sliceDensity = sliceDensity self.smooth = smooth self.data = None self._needUpload = False self.texture = None GLGraphicsItem.__init__(self) self.setGLOptions(glOptions) self.setData(data)
def setData(self, data): self.data = data self._needUpload = True self.update() def _uploadData(self): glEnable(GL_TEXTURE_3D) if self.texture is None: self.texture = glGenTextures(1) glBindTexture(GL_TEXTURE_3D, self.texture) if self.smooth: glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR) glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR) else: glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST) glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST) 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) shape = self.data.shape ## Test texture dimensions first glTexImage3D(GL_PROXY_TEXTURE_3D, 0, GL_RGBA, shape[0], shape[1], shape[2], 0, GL_RGBA, GL_UNSIGNED_BYTE, None) if glGetTexLevelParameteriv(GL_PROXY_TEXTURE_3D, 0, GL_TEXTURE_WIDTH) == 0: raise Exception("OpenGL failed to create 3D texture (%dx%dx%d); too large for this hardware." % shape[:3]) glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, shape[0], shape[1], shape[2], 0, GL_RGBA, GL_UNSIGNED_BYTE, self.data.transpose((2,1,0,3))) glDisable(GL_TEXTURE_3D) self.lists = {} for ax in [0,1,2]: for d in [-1, 1]: l = glGenLists(1) self.lists[(ax,d)] = l glNewList(l, GL_COMPILE) self.drawVolume(ax, d) glEndList() self._needUpload = False def paint(self): if self.data is None: return if self._needUpload: self._uploadData() self.setupGLState() glEnable(GL_TEXTURE_3D) glBindTexture(GL_TEXTURE_3D, self.texture) #glEnable(GL_DEPTH_TEST) #glDisable(GL_CULL_FACE) #glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) #glEnable( GL_BLEND ) #glEnable( GL_ALPHA_TEST ) glColor4f(1,1,1,1) view = self.view() center = QtGui.QVector3D(*[x/2. for x in self.data.shape[:3]]) cam = self.mapFromParent(view.cameraPosition()) - center #print "center", center, "cam", view.cameraPosition(), self.mapFromParent(view.cameraPosition()), "diff", cam cam = np.array([cam.x(), cam.y(), cam.z()]) ax = np.argmax(abs(cam)) d = 1 if cam[ax] > 0 else -1 glCallList(self.lists[(ax,d)]) ## draw axes glDisable(GL_TEXTURE_3D) def drawVolume(self, ax, d): N = 5 imax = [0,1,2] imax.remove(ax) tp = [[0,0,0],[0,0,0],[0,0,0],[0,0,0]] vp = [[0,0,0],[0,0,0],[0,0,0],[0,0,0]] nudge = [0.5/x for x in self.data.shape] tp[0][imax[0]] = 0+nudge[imax[0]] tp[0][imax[1]] = 0+nudge[imax[1]] tp[1][imax[0]] = 1-nudge[imax[0]] tp[1][imax[1]] = 0+nudge[imax[1]] tp[2][imax[0]] = 1-nudge[imax[0]] tp[2][imax[1]] = 1-nudge[imax[1]] tp[3][imax[0]] = 0+nudge[imax[0]] tp[3][imax[1]] = 1-nudge[imax[1]] vp[0][imax[0]] = 0 vp[0][imax[1]] = 0 vp[1][imax[0]] = self.data.shape[imax[0]] vp[1][imax[1]] = 0 vp[2][imax[0]] = self.data.shape[imax[0]] vp[2][imax[1]] = self.data.shape[imax[1]] vp[3][imax[0]] = 0 vp[3][imax[1]] = self.data.shape[imax[1]] slices = self.data.shape[ax] * self.sliceDensity r = list(range(slices)) if d == -1: r = r[::-1] glBegin(GL_QUADS) tzVals = np.linspace(nudge[ax], 1.0-nudge[ax], slices) vzVals = np.linspace(0, self.data.shape[ax], slices) for i in r: z = tzVals[i] w = vzVals[i] tp[0][ax] = z tp[1][ax] = z tp[2][ax] = z tp[3][ax] = z vp[0][ax] = w vp[1][ax] = w vp[2][ax] = w vp[3][ax] = w glTexCoord3f(*tp[0]) glVertex3f(*vp[0]) glTexCoord3f(*tp[1]) glVertex3f(*vp[1]) glTexCoord3f(*tp[2]) glVertex3f(*vp[2]) glTexCoord3f(*tp[3]) glVertex3f(*vp[3]) glEnd()
## Interesting idea: ## remove projection/modelview matrixes, recreate in texture coords. ## it _sorta_ works, but needs tweaking. #mvm = glGetDoublev(GL_MODELVIEW_MATRIX) #pm = glGetDoublev(GL_PROJECTION_MATRIX) #m = QtGui.QMatrix4x4(mvm.flatten()).inverted()[0] #p = QtGui.QMatrix4x4(pm.flatten()).inverted()[0] #glMatrixMode(GL_PROJECTION) #glPushMatrix() #glLoadIdentity() #N=1 #glOrtho(-N,N,-N,N,-100,100) #glMatrixMode(GL_MODELVIEW) #glLoadIdentity() #glMatrixMode(GL_TEXTURE) #glLoadIdentity() #glMultMatrixf(m.copyDataTo()) #view = self.view() #w = view.width() #h = view.height() #dist = view.opts['distance'] #fov = view.opts['fov'] #nearClip = dist * .1 #farClip = dist * 5. #r = nearClip * np.tan(fov) #t = r * h / w #p = QtGui.QMatrix4x4() #p.frustum( -r, r, -t, t, nearClip, farClip) #glMultMatrixf(p.inverted()[0].copyDataTo()) #glBegin(GL_QUADS) #M=1 #for i in range(500): #z = i/500. #w = -i/500. #glTexCoord3f(-M, -M, z) #glVertex3f(-N, -N, w) #glTexCoord3f(M, -M, z) #glVertex3f(N, -N, w) #glTexCoord3f(M, M, z) #glVertex3f(N, N, w) #glTexCoord3f(-M, M, z) #glVertex3f(-N, N, w) #glEnd() #glDisable(GL_TEXTURE_3D) #glMatrixMode(GL_PROJECTION) #glPopMatrix()