Question

在mac上使用psychopy ver 1.81.03我想在图像上绘制多边形（例如三角形）。到目前为止，我的图像始终位于顶部，因此隐藏了多边形，无论我将它们放入的顺序如何。如果我的多边形比图像晚一帧开始，这也保持不变。

e.g。请看下面的代码（在编译之前用Builder创建）如何在蓝色方块和红色三角形开始在第0帧开始，但是当你运行它时，蓝色方块总是覆盖红色三角形！？

有没有办法让多边形在顶部？在绘制它们之前，我是否需要合并图像和多边形？

非常感谢你的帮助!!

塞巴斯蒂安

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
"""
This experiment was created using PsychoPy2 Experiment Builder (v1.81.03), Sun Jan 18 20:44:26 2015
If you publish work using this script please cite the relevant PsychoPy publications
  Peirce, JW (2007) PsychoPy - Psychophysics software in Python. Journal of Neuroscience Methods, 162(1-2), 8-13.
  Peirce, JW (2009) Generating stimuli for neuroscience using PsychoPy. Frontiers in Neuroinformatics, 2:10. doi: 10.3389/neuro.11.010.2008
"""

from __future__ import division  # so that 1/3=0.333 instead of 1/3=0
from psychopy import visual, core, data, event, logging, sound, gui
from psychopy.constants import *  # things like STARTED, FINISHED
import numpy as np  # whole numpy lib is available, prepend 'np.'
from numpy import sin, cos, tan, log, log10, pi, average, sqrt, std, deg2rad, rad2deg, linspace, asarray
from numpy.random import random, randint, normal, shuffle
import os  # handy system and path functions

# Ensure that relative paths start from the same directory as this script
_thisDir = os.path.dirname(os.path.abspath(__file__))
os.chdir(_thisDir)

# Store info about the experiment session
expName = u'test_triangle_over_square'  # from the Builder filename that created this script
expInfo = {'participant':'', 'session':'001'}
dlg = gui.DlgFromDict(dictionary=expInfo, title=expName)
if dlg.OK == False: core.quit()  # user pressed cancel
expInfo['date'] = data.getDateStr()  # add a simple timestamp
expInfo['expName'] = expName

# Data file name stem = absolute path + name; later add .psyexp, .csv, .log, etc
filename = _thisDir + os.sep + 'data/%s_%s_%s' %(expInfo['participant'], expName, expInfo['date'])

# An ExperimentHandler isn't essential but helps with data saving
thisExp = data.ExperimentHandler(name=expName, version='',
    extraInfo=expInfo, runtimeInfo=None,
    originPath=None,
    savePickle=True, saveWideText=True,
    dataFileName=filename)
#save a log file for detail verbose info
logFile = logging.LogFile(filename+'.log', level=logging.EXP)
logging.console.setLevel(logging.WARNING)  # this outputs to the screen, not a file

endExpNow = False  # flag for 'escape' or other condition => quit the exp

# Start Code - component code to be run before the window creation

# Setup the Window
win = visual.Window(size=(1280, 800), fullscr=True, screen=0, allowGUI=False, allowStencil=False,
    monitor='testMonitor', color=[0,0,0], colorSpace='rgb',
    blendMode='avg', useFBO=True,
    )
# store frame rate of monitor if we can measure it successfully
expInfo['frameRate']=win.getActualFrameRate()
if expInfo['frameRate']!=None:
    frameDur = 1.0/round(expInfo['frameRate'])
else:
    frameDur = 1.0/60.0 # couldn't get a reliable measure so guess

# Initialize components for Routine "trial"
trialClock = core.Clock()
ISI = core.StaticPeriod(win=win, screenHz=expInfo['frameRate'], name='ISI')
square = visual.ImageStim(win=win, name='square',units='pix', 
    image=None, mask=None,
    ori=0, pos=[0, 0], size=[200, 200],
    color=u'blue', colorSpace='rgb', opacity=1,
    flipHoriz=False, flipVert=False,
    texRes=128, interpolate=True, depth=-1.0)
polygon = visual.ShapeStim(win=win, name='polygon',units='pix', 
    vertices = [[-[200, 300][0]/2.0,-[200, 300][1]/2.0], [+[200, 300][0]/2.0,-[200, 300][1]/2.0], [0,[200, 300][1]/2.0]],
    ori=0, pos=[0, 0],
    lineWidth=1, lineColor=[1,1,1], lineColorSpace='rgb',
    fillColor=u'red', fillColorSpace='rgb',
    opacity=1,interpolate=True)

# Create some handy timers
globalClock = core.Clock()  # to track the time since experiment started
routineTimer = core.CountdownTimer()  # to track time remaining of each (non-slip) routine 

#------Prepare to start Routine "trial"-------
t = 0
trialClock.reset()  # clock 
frameN = -1
# update component parameters for each repeat
# keep track of which components have finished
trialComponents = []
trialComponents.append(ISI)
trialComponents.append(square)
trialComponents.append(polygon)
for thisComponent in trialComponents:
    if hasattr(thisComponent, 'status'):
        thisComponent.status = NOT_STARTED

#-------Start Routine "trial"-------
continueRoutine = True
while continueRoutine:
    # get current time
    t = trialClock.getTime()
    frameN = frameN + 1  # number of completed frames (so 0 is the first frame)
    # update/draw components on each frame

    # *square* updates
    if frameN >= 0 and square.status == NOT_STARTED:
        # keep track of start time/frame for later
        square.tStart = t  # underestimates by a little under one frame
        square.frameNStart = frameN  # exact frame index
        square.setAutoDraw(True)

    # *polygon* updates
    if frameN >= 0 and polygon.status == NOT_STARTED:
        # keep track of start time/frame for later
        polygon.tStart = t  # underestimates by a little under one frame
        polygon.frameNStart = frameN  # exact frame index
        polygon.setAutoDraw(True)
    # *ISI* period
    if t >= 0.0 and ISI.status == NOT_STARTED:
        # keep track of start time/frame for later
        ISI.tStart = t  # underestimates by a little under one frame
        ISI.frameNStart = frameN  # exact frame index
        ISI.start(0.5)
    elif ISI.status == STARTED: #one frame should pass before updating params and completing
        ISI.complete() #finish the static period

    # check if all components have finished
    if not continueRoutine:  # a component has requested a forced-end of Routine
        routineTimer.reset()  # if we abort early the non-slip timer needs reset
        break
    continueRoutine = False  # will revert to True if at least one component still running
    for thisComponent in trialComponents:
        if hasattr(thisComponent, "status") and thisComponent.status != FINISHED:
            continueRoutine = True
            break  # at least one component has not yet finished

    # check for quit (the Esc key)
    if endExpNow or event.getKeys(keyList=["escape"]):
        core.quit()

    # refresh the screen
    if continueRoutine:  # don't flip if this routine is over or we'll get a blank screen
        win.flip()
    else:  # this Routine was not non-slip safe so reset non-slip timer
        routineTimer.reset()

#-------Ending Routine "trial"-------
for thisComponent in trialComponents:
    if hasattr(thisComponent, "setAutoDraw"):
        thisComponent.setAutoDraw(False)
win.close()
core.quit()

Answer 1

根据Jonas＆＃39;在上面的评论中，PsychoPy使用了一个分层系统，其中后续的刺激被绘制在之前的刺激之上（如他的代码示例中所示）。

在图形构建器环境中，绘制顺序由刺激成分的垂直顺序表示：顶部的刺激首先被绘制，而下部的刺激逐渐被分层。

您可以通过右键单击刺激组件的顺序并根据需要选择＆＃34;上移＆＃34;，＆＃34;向下移动＆＃34;等来更改刺激组件的顺序。

然而，塞巴斯蒂安已经发现了一个错误，因为ImageStim和ShapeStim组件之间没有遵守预期的绘制顺序。作为解决方法，您可以使用ImageStim显示位图表示替换ShapeStim。多个ImageStims应该正确绘制（多个ShapeStims也是如此）。要使其在另一个图像上正确绘制，请务必将其另存为.png文件，该文件支持透明度。这样，只会在顶部绘制实际形状，因为其背景像素可以设置为透明，并且不会遮盖底层图像。

对于长期解决方案，我已将您的问题作为错误报告添加到PsychoPy GitHub项目中： https://github.com/psychopy/psychopy/issues/795

Answer 2

原来，它是Builder中Polygon组件中的一个错误。

这在即将发布的版本（1.82.00）中已修复。可以看到进行修复所需的更改 https://github.com/psychopy/psychopy/commit/af1af9a7a85cee9b4ec8ad5e2ff1f03140bd1a36 如果您愿意，可以将其添加到您自己的安装中。

欢呼声，乔恩

在图像顶部的心理多边形

2 个答案: