Add example of using scalar fields

Author: tmontaigu

docs/examples.rst

@@ -21,6 +21,12 @@ Loading a file
 .. literalinclude:: ../script_examples/loading_a_file.py
     :language: Python
 
+Scalar Field
+------------
+
+.. literalinclude:: ../script_examples/scalar_field.py
+    :language: Python
+
 
 Sub sampling
 ------------

script_examples/scalar_field.py

@@ -0,0 +1,41 @@
+"""Example that shows how to add a scalar field
+as well as how to make it properly be displayed in the UI
+"""
+import pycc
+import numpy as np
+
+xs = np.arange(0.0, 5.0, 0.1, pycc.PointCoordinateType)
+ys = np.ones(len(xs), pycc.PointCoordinateType) * 18.5
+zs = np.ones(len(xs), pycc.PointCoordinateType) * 17.33
+
+pc = pycc.ccPointCloud(xs, ys, zs)
+
+# Create and add a new scalar field
+idx = pc.addScalarField("Intensity")
+scalar_field = pc.getScalarField(idx)
+
+# Change the values
+sfArray = pc.getScalarField(idx).asArray()
+num_chunk = 4
+chunk_size = len(xs) // num_chunk
+for i in range(num_chunk):
+    sfArray[i*chunk_size:(i+1)*chunk_size] = i
+
+# Make it so the scalar field is displayed
+scalar_field.computeMinAndMax()
+pc.setCurrentDisplayedScalarField(idx)
+pc.showSF(True)
+
+# Optional: choose the color scale
+scale = pycc.ccColorScalesManager.GetDefaultScale(
+    pycc.ccColorScalesManager.YELLOW_BROWN
+)
+scalar_field.setColorScale(scale)
+
+pc.setName("Scalar Field Example")
+# Change the point size so that the cloud is more
+# visible by default (only needed here as the point cloud
+# is very small)
+pc.setPointSize(7)
+
+pycc.GetInstance().addToDB(pc)