head_pointing_to_end_trials.py

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# -*- coding: utf-8 -*-
"""
...\PTVR_Researchers\Python_Scripts\Demos\Pointing\events_and_callbacks_for_pointing\
    head_pointing_to_end_trials.py
 
Description :
    Loop of trials with one scene per trial.
    You must point at the sphere (whose position changes across trials) with 
    your head to go to the next trial.
    
 
 
        
 
"""
 
import PTVR.SystemUtils
import PTVR.Visual as visual
import PTVR.Stimuli.Scenes
import PTVR.Stimuli.Objects
import PTVR.Stimuli.UIObjects
import PTVR.Data.Event as event
import PTVR.Data.Callback as callback
import PTVR.Stimuli.Color as color
 
from PTVR.Pointing.PointingCursor import *
import PTVR.Pointing.ReticleImageFromDrawing as RG
 
nb_of_trials = 4
 
# radius of the pointing activation disk (in degrees)
pointing_activation_disk_radius_deg = 3
# increase this parameter to make pointing easier
 
distance_to_sphere = 3  # in meters
 
reticle_size_deg = 2 * pointing_activation_disk_radius_deg
# The reticle's diameter is thus equal to the diameter of the pointing
# activation disk.
 
 
def create_reticle(my_scene):
    # The RETICLE
    # This function creates the head-contingent reticle.
    # This reticle is a head-contingent visual feedback which is not responsible for
    # the pointing process. The latter is performed thanks to the 'pointedAt' events
    # created further below.
    #
    # internally create a PNG file to create a sprite
    reticle_2D_image = RG.ReticleImageFromDrawing()
 
    # transform 'reticle_2D_image' into a contingent cursor.
    my_reticle = ImageToContingentCursor(
        image=reticle_2D_image,
        size_in_degrees=[reticle_size_deg, reticle_size_deg],
        distance_if_empty_cursor_cone=distance_to_sphere
    )
    my_scene.place_contingent_cursor(my_reticle)
    # END of Reticle creation.
    # -------------------------
 
 
def main():
 
    my_world = visual.The3DWorld(name_of_subject="nabil")
    my_world.translate_coordinate_system_along_global(np.array([0, 1.2, 0]))
    text_1 = PTVR.Stimuli.Objects.Text(text="Point at sphere with your head to go to next trial",
                                       fontsize_in_postscript_points=200,
        vertical_alignment="baseline")
    text_1.set_cartesian_coordinates(y=-2, z=2)
 
    for i in range(0, nb_of_trials):
        trial_scene = PTVR.Stimuli.Scenes.VisualScene(trial=i + 1)
        trial_text = PTVR.Stimuli.Objects.Text(text="trial : " +
                                               str(trial_scene.trial),
                                               fontsize_in_postscript_points=600,
        vertical_alignment="baseline")
        trial_text.set_cartesian_coordinates(z=2)
 
        my_target_sphere = PTVR.Stimuli.Objects.Sphere(
            color=color.RGBColor(1, 0, 0, 1),
            size_in_meters=0.2)
        my_target_sphere.set_perimetric_coordinates(eccentricity=20,
                                                    halfMeridian=i * 90,
                                                    radialDistance=4)
 
        # if you do not want to have a flat cursor to get visual feedback from your head's
        # motion and thus see if you're pointing correctly at the sphere,
        # then comment the following line.
        create_reticle(trial_scene)
 
        # Interactions allowing us to point at objects
        # Events and Callbacks must be created BEFORE interactions !
        # Events
        target_is_pointed_at =  \
            event.PointedAt(
                # What is the object that must be pointed at?
                target_id=my_target_sphere.id,
 
                # Id of the pointing device:
                # Headset is the default (shown below for didactic emphasis)
                activation_cone_origin_id=my_world.headset.id,
 
                activation_cone_radius_deg=pointing_activation_disk_radius_deg)
 
        # Create interaction for the current scene
        my_callback_current_scene_end = callback.EndCurrentScene()
 
        # Standard Interaction
        trial_scene.AddInteraction(events=[target_is_pointed_at],
                                   callbacks=[my_callback_current_scene_end])
 
        trial_scene.place(trial_text, my_world)
        trial_scene.place(text_1, my_world)
 
        trial_scene.place(my_target_sphere, my_world)
        my_world.add_scene(trial_scene)
 
    my_world.write()  # Write experiment to .json file
 
 
if __name__ == "__main__":
    main()
    PTVR.SystemUtils.LaunchThe3DWorld()