Controls¶

View manipulation. The camera look at position is denoted by a red-green-blue cursor, with segments corresponding to x, y and z axes. Perform LMB drag to rotate the viewpoint in a turntable fashion. Perform LMB drag while hold Shift to pan the viewpoint. Double clicking the LMB moves the look at position to a point near the mouse cursor.

Point selection. Hold Ctrl/Ctrl-Shift while LMB dragging a box to add/remove points to the current selection. Hold Ctrl/Ctrl-Shift while LMB clicking on a point to add/remove a single point from the current selection. Click the RMB to clear the current selection. Use pptk.viewer.get() to query the selected point indices.

Hot keys.

Methods¶

class pptk.viewer(*args, **kwargs)¶

__init__(*args, **kwargs)¶

Opens a point cloud viewer

Examples

Create 100 random points

>>> xyz = pptk.rand(100, 3)

Visualize the points

>>> v = pptk.viewer(xyz)
>>> v.set(point_size=0.005)

Visualize points shaded by height

>>> v = pptk.viewer(xyz, xyz[:, 2])
>>> v.set(point_size=0.005)

Visualize points shaded by random RGB color

>>> rgb = pptk.rand(100, 3)
>>> pptk.viewer(xyz, rgb)
>>> v.set(point_size=0.005)

attributes(*attr)¶

Loads point attributes

The loaded attributes are used to clor the currently loaded point cloud. Supposing n points loaded, this function accepts attributes of the following forms:

• scalars: 1-d array of length 1 or n
• RGB colors: 2-d array of shape (1, 3) or (n, 3)
• RGBA colors: 2-d array of shape (1, 4) or (n, 4)

Passing in no arguments clears all existing attribute sets and colors all points white. Cycle through attribute sets via [ and ] keys.

Examples:

>>> xyz = pptk.rand(100, 3)
>>> v = pptk.viewer(xyz)
>>> attr1 = pptk.rand(100)     # 100 random scalars
>>> attr2 = pptk.rand(100, 3)  # 100 random RGB colors
>>> attr3 = pptk.rand(100, 4)  # 100 random RGBA colors
>>> attr4 = pptk.rand(1)       # 1 random scalar
>>> attr5 = pptk.rand(1, 3)    # 1 random RGB color
>>> attr6 = pptk.rand(1, 4)    # 1 random RGBA color
>>> v.attributes(attr1, attr2, attr3, attr4, attr5, attr6)
>>> v.set(point_size=0.005)

capture(filename)¶

Take screen shot of current view and save to filename

Examples:

>>> v = pptk.viewer(xyz)
>>> v.capture('screenshot.png')

clear()¶

Removes the current point cloud in the viewer

Examples

>>> v.clear()

close()¶

Closes the point cloud viewer

Examples

>>> v.close()

color_map(c, scale=None)¶

Specifies how scalar attributes are used to color points in the viewer.

Input c is expected to be an array of n RGB (or RGBA) vectors (i.e. c is a n x 3 or n x 4 numpy array). Upon return, scalar values equal to scale 0 are colored with c[0], scale[1] with c[-1], and scalars in between appropriately interpolated. If scale is None, scale is automatically set as the minimum and maximum scalar values in the current attribute set.

Alternatively, one can choose from a number of preset color maps by passing the corresponding string instead.

Preset color maps
‘jet’ (default)
‘hsv’
‘hot’
‘cool’
‘spring’
‘summer’
‘autumn’
‘winter’
‘gray’

Examples

>>> xyz = np.c_[np.arange(10), np.zeros(10), np.zeros(10)]
>>> scalars = np.arange(10)
>>> v = pptk.viewer(xyz, scalars)
>>> v.set(point_size=0.1)
>>> v.color_map('cool', scale=[0, 5])
>>> v.color_map([[0, 0, 0], [1, 1, 1]])

get(prop_name)¶

Gets viewer property

Property Name	Return Type	Description
curr_atribute_id	uint	Current attribute set index
eye	3 x float64	Camera position
lookat	3 x float64	Camera look-at position
mvp	4 x 4 float64
num_points	uint	Number of points loaded
num_attributes	uint	Number of attribute sets loaded
phi	float64	Camera azimuthal angle (radians)
r	float64	Camera distance to look-at point
right	3 x float64	Camera Right vector
selected	? x int32	Indices of selected points
theta	float64	Camera elevation angle (radians)
up	3 x float64	Camera up vector
view	3 x float64	Camera view vector

Examples

>>> v = pptk.viewer(xyz)
>>> v.get('selected')

play(poses, ts=[], tlim=[-inf, inf], repeat=False, interp='cubic_natural')¶

Plays back camera path animation specified by poses

Parameters:

poses – Key poses. e.g. a list of 6-tuples (x, y, z, phi, theta, r) poses, or anything convertible to a 6-column array by np.array ts (optional) – Key pose times. If unspecified key poses are placed at 1 second intervals. tlim (optional) – Play back time range (in seconds) repeat (optional) – Toggles infinite play back loop. Works well with interp=’cubic_periodic’. interp (optional) – Interpolation method. Should be one of ‘constant’, ‘linear’, ‘cubic_natural’, or ‘cubic_periodic’.

Examples:

Rotate camera about origin at 1/8 Hz.

>>> poses = []
>>> poses.append([0, 0, 0, 0 * np.pi/2, np.pi/4, 5])
>>> poses.append([0, 0, 0, 1 * np.pi/2, np.pi/4, 5])
>>> poses.append([0, 0, 0, 2 * np.pi/2, np.pi/4, 5])
>>> poses.append([0, 0, 0, 3 * np.pi/2, np.pi/4, 5])
>>> poses.append([0, 0, 0, 4 * np.pi/2, np.pi/4, 5])
>>> v.play(poses, 2 * np.arange(5), repeat=True, interp='linear')

record(folder, poses, ts=[], tlim=[-inf, inf], interp='cubic_natural', shutter_speed=inf, fps=24, prefix='frame_', ext='png')¶

Records camera animation to a sequence of images. Usage of this method is very similar to viewer.play(…).

Parameters:	folder – Folder to which images are saved poses – Same as in pptk.viewer.play() ts – Same as in pptk.viewer.play() tlim – Same as in pptk.viewer.play() interp – Same as in pptk.viewer.play() fps – Frames per second prefix – Resulting image file names are prefixed with this string ext – Image format

Examples

Assuming poses defined as in the example for :meth:pptk.viewer.play

>>> mkdir 'recording'
>>> v.record('recording', poses)

Tip: Uses ffmpeg to generate a video from the resulting image sequence

>>> ffmpeg -i "frame_%03d.png" -c:v mpeg4 -qscale:v 0 -r 24 output.mp4

reset()¶

Resets the viewer

set(**kwargs)¶

Sets viewer property

Property Name	Value Type	Description
bg_color	4 x float32	Background color in RGBA [0, 1]
bg_color_top	4 x float32	Top background color
bg_color_bottom	4 x float32	Bottom background color
color_map	? x 4 x float32	Color map; array of RGBA’s [0, 1]
color_map_scale	2 x float32	Color map scaling interval
curr_attribute_id	uint	Current attribute set index
floor_level	float32	Floor z-level
floor_color	4 x float32	Floor color in RGBA [0, 1]
lookat	3 x float32	Camera look-at position
phi	float32	Camera azimuthal angle (radians)
point_size	float32	Point size in world space
r	float32	Camera distance to look-at point
selected	? x uint	Indices of selected points
show_grid	bool	Show floor grid
show_info	bool	Show information text overlay
show_axis	bool	Show axis / look-at cursor
theta	float32	Camera elevation angle (radians)

(phi, theta, r) are spherical coordinates specifying camera position relative to the look at position.

(right, up, view) are orthogonal vectors forming the camera coordinate frame, where view is pointed away from the look at position, and view is the cross product of up with right

Examples

>>> v = pptk.viewer(xyz)
>>> v.set(point_size = 0.01)

wait()¶

Blocks until Enter/Return key is pressed in viewer

Examples

>>> v = pptk.viewer(xyz)
>>> v.wait()

Press enter in viewer to return control to python terminal.