Obtaining Positional Data

[farshizzo]

Yes, this is how most people implement crosshairs for stereo viewing. Here is a sample script that will place a crosshair 0.1 meters in front of the user.

import viz
viz.go(viz.STEREO)

viz.add('tut_ground.wrl')
viz.clearcolor(viz.GRAY)

crosshair = viz.add(viz.TEXQUAD)
crosshair.texture(viz.add('crosshair.png'))
crosshair.scale(0.01,0.01,0.01)

viz.mouse(viz.OFF)

def ontimer(num):
	line = viz.screentoworld(viz.mousepos())
	v = viz.Vector(viz.get(viz.HEAD_POS))
	dir = viz.Vector(line[3:]) - viz.Vector(line[:3])
	dir.normalize()
	dir *= 0.1 #Place crosshair 1/10th meter in front of user
	v += dir
	crosshair.translate(v.get())
	crosshair.rotatequat(viz.get(viz.VIEW_QUAT))
	
viz.callback(viz.TIMER_EVENT,ontimer)
viz.starttimer(0,0,viz.FOREVER)

[betancourtb82]

Ok, I implemented the crosshair as you said, however I'm still getting an offset between the bullet and the crosshair. Is there anyway to correct this now that I am using the "3d" version of the crosshair? I've attached a copy of the code.

[farshizzo]

I tried your script but I didn't see any bullet. I've modified my previous code so that it shoots a bullet from the center of the viewpoint towards the direction of the crosshair. There will always be an apparent offset between the crosshair and the bullet due to binocular vision.

import viz
viz.go(viz.STEREO)

viz.add('tut_ground.wrl')
viz.clearcolor(viz.GRAY)

crosshair = viz.add(viz.TEXQUAD)
crosshair.texture(viz.add('crosshair.png'))
crosshair.scale(0.01,0.01,0.01)

viz.mouse(viz.OFF)

def ontimer(num):
	line = viz.screentoworld(viz.mousepos())
	v = viz.Vector(viz.get(viz.HEAD_POS))
	dir = viz.Vector(line[3:]) - viz.Vector(line[:3])
	dir.normalize()
	dir *= 0.1 #Place crosshair 1/10th meter in front of user
	v += dir
	crosshair.translate(v.get())
	crosshair.rotatequat(viz.get(viz.VIEW_QUAT))
	
viz.callback(viz.TIMER_EVENT,ontimer)
viz.starttimer(0,0,viz.FOREVER)

bullet = viz.add('white_ball.wrl')

def shoot():
	pos = viz.Vector(viz.get(viz.HEAD_POS))
	dir = viz.Vector(crosshair.get(viz.POSITION)) - pos
	dir.normalize()
	dir *= 10
	bullet.translate(pos.get())
	bullet.goto((pos+dir).get(),3)
vizact.onmousedown(viz.MOUSEBUTTON_LEFT,shoot)

[betancourtb82]

I apologize. I think I sent you something I was working on earlier but I corrected it. I still get the same behavior. Would you mind taking a look at this one and let me know if there is something wrong? Thanks

[farshizzo]

In both calls to viz.screentoworld you are adding an offset to the x position. You don't need to do this when using a 3D cursor. Also, after adding the cursor you should disable collisions on it so the bullet does not hit it.

crosshair.disable(viz.COLLISION)