Want both sinusoids to be full brightness, not half masked

drifting_example.py

from direct.showbase.ShowBase import ShowBase
from panda3d.core import Texture, CardMaker, TextureStage, TransparencyAttrib
import numpy as np 
from direct.gui.OnscreenText import OnscreenText 
from direct.task import Task

#Create sin
texSize = 512
frequency = 8
def sin3d(X, freq = 1):
    return np.sin(X*freq)
def sin8bit(X, freq = 1):
    sin_float = sin3d(X, freq=freq)
    sin_pos = (sin_float+1)*127.5; #from 0-255
    return np.asarray(sin_pos, dtype = np.uint8)
x = np.linspace(0, 2*np.pi, texSize)  #could try texSize+1 and then get meshgrid with x[0:-1] not perfect
y = np.linspace(0, 2*np.pi, texSize)
X, Y = np.meshgrid(x,y)
sinTex = sin8bit(X, freq = frequency);

#Create masks
leftMask = 255*np.ones((texSize,texSize), dtype=np.uint8)      #127.5
leftMask[:, :texSize//2 + bandRadius] = 0
rightMask = 255*np.ones((texSize,texSize), dtype=np.uint8)      #127.5
rightMask[:, texSize//2 - bandRadius:] = 0  #Check index on this

#Properties of stimulus
bandRadius = 10
rotation = 30

class MyApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)

        #CREATE TEXTURE STAGES
        #Sine
        self.sinTexture = Texture("sin")
        self.sinTexture.setup2dTexture(texSize, texSize, Texture.T_unsigned_byte, Texture.F_luminance) 
        self.sinTexture.setRamImage(sinTex)   
        self.sinTextureStage = TextureStage('sin')
        #Mask left (with card 1)
        self.leftMaskTex = Texture("left_mask")
        self.leftMaskTex.setup2dTexture(texSize, texSize, Texture.T_unsigned_byte, Texture.F_luminance) 
        self.leftMaskTex.setRamImage(leftMask)  
        self.leftMaskTexStage = TextureStage('left_mask')
        #Mask right (with card 2)
        self.rightMaskTex = Texture("right_mask")
        self.rightMaskTex.setup2dTexture(texSize, texSize, Texture.T_unsigned_byte, Texture.F_luminance) 
        self.rightMaskTex.setRamImage(rightMask)  
        self.rightMaskTexStage = TextureStage('right_mask')
                                                                           
        #CREATE CARDS/SCENEGRAPH
        cm = CardMaker('card1')
        cm.setFrameFullscreenQuad()
        self.card1 = self.aspect2d.attachNewNode(cm.generate())
        self.card2 = self.aspect2d.attachNewNode(cm.generate())
        
        #SET TEXTURE STAGES
        self.card1.setTexture(self.sinTextureStage, self.sinTexture)  #ts, tx
        self.card1.setTexture(self.leftMaskTexStage, self.leftMaskTex)
        self.card2.setTexture(self.sinTextureStage, self.sinTexture)  #ts, tx
        self.card2.setTexture(self.rightMaskTexStage, self.rightMaskTex)
        
        #Set attributes so you can see both cards
        #self.card2.setTransparency(TransparencyAttrib.MAlpha)  #enable transparency
        #self.card2.setAlphaScale(0.5) #
        #Set attributes so both show brightly (do not use transparency attrib that's a trap)
        self.setBackgroundColor((0, 0, 0, 1))
        self.card1.setAttrib(ColorBlendAttrib.make(ColorBlendAttrib.M_add))
        self.card2.setAttrib(ColorBlendAttrib.make(ColorBlendAttrib.M_add))
        
               
        #BASIC TRANSFORMS
        self.card1.setScale(np.sqrt(2))
        self.card1.setR(rotation) 
        self.card2.setScale(np.sqrt(2))
        self.card2.setR(rotation) 
        
        self.title = OnscreenText("x",
                                  style = 1,
                                  fg = (1,1,1,1),
                                  bg = (0, 0, 0, 1),
                                  pos = (0,0), 
                                  scale = 0.06)
        
        #Add texture move procedure to the task manager
        self.taskMgr.add(self.moveTextureTask, "moveTextureTask")
        
    #Procedure to move the textures
    def moveTextureTask(self, task):
        shiftMag = task.time*0.15
        self.card1.setTexPos(self.sinTextureStage, shiftMag, 0, 0) #u, v, w
        self.card2.setTexPos(self.sinTextureStage, -shiftMag, 0, 0) #u, v, w
        return Task.cont #as long as this is returned, the taskMgr will continue to call it

if __name__ == '__main__':
    app = MyApp()
    app.run()