Merge pull request #68 from martinRenou/warpbyscalar

WarpByScalar

Author: martinRenou

docs/source/api_reference/warpbyscalar.rst

@@ -0,0 +1,50 @@
+WarpByScalar
+============
+
+The ``WarpByScalar`` widget will modify the mesh geometry.
+
+It is similar to ``Paraview``, ``PyVista`` and ``vtk``'s warp-by-scalar effect, but instead of computing the transformation on the CPU,
+it is entirely computed on the GPU. Which means that changing the warp factor does not involve looping over the mesh vertices,
+we only send the new ``factor`` value to the GPU.
+
+The ``input`` attribute should be a 1-D data. For example, if your mesh has a 1-D ``Data`` named ``"height"``, your can set the input to be:
+
+.. code::
+
+    warped_mesh = WarpByScalar(mesh, input='height')  # Warp by 'height' data
+
+
+Examples
+--------
+
+.. code:: Python
+
+    from pyvista import examples
+    import numpy as np
+
+    from ipywidgets import VBox, FloatSlider
+    from ipygany import PolyMesh, Scene, IsoColor, WarpByScalar
+
+    pvmesh = examples.download_topo_global()
+    ugrid = pvmesh.cast_to_unstructured_grid()
+
+    from ipygany import PolyMesh, Scene, IsoColor, WarpByScalar
+
+    # Turn the PyVista mesh into a PolyMesh
+    mesh = PolyMesh.from_vtk(ugrid)
+
+    colored_mesh = IsoColor(mesh, min=-10421.0, max=6527.0)
+    warped_mesh = WarpByScalar(colored_mesh, input='altitude', factor=0.5e-5)
+
+    # Link a slider to the warp value
+    warp_slider = FloatSlider(min=0., max=5., value=0.5)
+
+    def on_slider_change(change):
+        warped_mesh.factor = change['new'] * 1e-5
+
+    warp_slider.observe(on_slider_change, 'value')
+
+    VBox((warp_slider, Scene([warped_mesh])))
+
+.. image:: warpscalar.gif
+   :alt: warpscalar

docs/source/api_reference/warpscalar.gif

@@ -17,7 +17,7 @@ If you have under-water meshes on which you want to cast caustics, you need to c
 
 Then you'll need to pass those under-water meshes to the water effect:
 
-.. code::
+.. code:: Python
 
     underwater_mesh1 = UnderWater(mesh1, input='underwater')
     underwater_mesh2 = UnderWater(mesh2, input='underwater')

docs/source/api_reference/water.rst

@@ -26,6 +26,7 @@ ipygany: Scientific visualization in the Jupyter notebook
 
     api_reference/isocolor
     api_reference/warp
+    api_reference/warpbyscalar
     api_reference/threshold
 
 .. toctree::

docs/source/index.rst

@@ -8,7 +8,8 @@
     PolyMesh, TetraMesh, PointCloud,
     Scene,
     Data, Component,
-    Alpha, RGB, IsoColor, Threshold, IsoSurface, Warp,
+    Alpha, RGB, IsoColor, Threshold, IsoSurface,
+    Warp, WarpByScalar,
     Water, UnderWater
 )
 from ._version import __version__, version_info  # noqa

ipygany/__init__.py

@@ -529,6 +529,19 @@ def input_dim(self):
         return 3
 
 
+class WarpByScalar(Effect):
+    """A warp-by-scalar effect to another block."""
+
+    _model_name = Unicode('WarpByScalarModel').tag(sync=True)
+
+    factor = CFloat(1.).tag(sync=True)
+
+    @property
+    def input_dim(self):
+        """Input dimension."""
+        return 1
+
+
 class Alpha(Effect):
     """An transparency effect to another block."""
 

ipygany/ipygany.py

@@ -53,7 +53,7 @@
     "@jupyter-widgets/controls": "^2.0.0",
     "backbone": "^1.4.0",
     "binary-search-tree": "^0.2.6",
-    "ganyjs": "^0.6.2",
+    "ganyjs": "^0.6.3",
     "three": "^0.118.0",
     "uuid": "^3.3.3"
   },

package.json

@@ -27,7 +27,7 @@ import {
   Data, Component,
   Block, Effect,
   PolyMesh, TetraMesh, PointCloud,
-  Warp, Alpha, RGB, IsoColor, IsoSurface, Threshold,
+  Warp, WarpByScalar, Alpha, RGB, IsoColor, IsoSurface, Threshold,
   Water, UnderWater,
 } from 'ganyjs';
 
@@ -409,6 +409,40 @@ class WarpModel extends EffectModel {
 }
 
 
+export
+class WarpByScalarModel extends EffectModel {
+
+  defaults() {
+    return {...super.defaults(),
+      _model_name: WarpByScalarModel.model_name,
+    };
+  }
+
+  get input () {
+    return this.get('input');
+  }
+
+  get factor () {
+    return this.get('factor');
+  }
+
+  createBlock () {
+    return new WarpByScalar(this.parent.block, this.input, this.factor);
+  }
+
+  initEventListeners () : void {
+    super.initEventListeners();
+
+    this.on('change:factor', () => { this.block.factor = this.factor; });
+  }
+
+  block: WarpByScalar;
+
+  static model_name = 'WarpByScalarModel';
+
+}
+
+
 export
 class AlphaModel extends EffectModel {