Transforming data with Pipelines

Pipelines are the construct used to compose filters that transform the published input data into new meshes. This is where users specify typical geometric transforms (e.g., clipping and slicing), field based transforms (e.g., threshold and contour), etc. The resulting data from each Pipeline can be used as input to Scenes or Extracts. Each pipeline contains one or more filters that transform the published mesh data. See Ascent’s Scenes docs for deeper details on Pipelines.

Calculating and rendering contours

C++

#include <iostream>
#include "ascent.hpp"
#include "conduit_blueprint.hpp"

using namespace ascent;
using namespace conduit;

int main(int argc, char **argv)
{
    //create example mesh using the conduit blueprint braid helper
    
    Node mesh;
    conduit::blueprint::mesh::examples::braid("hexs",
                                              25,
                                              25,
                                              25,
                                              mesh);

    // Use Ascent to calculate and render contours

    Ascent a;

    // open ascent
    a.open();

    // publish mesh to ascent
    a.publish(mesh);

    // setup actions
    Node actions;
    Node &add_act = actions.append();
    add_act["action"] = "add_pipelines";
    Node &pipelines = add_act["pipelines"];

    // create a  pipeline (pl1) with a contour filter (f1)
    pipelines["pl1/f1/type"] = "contour";

    // extract contours where braid variable
    // equals 0.2 and 0.4
    Node &contour_params = pipelines["pl1/f1/params"];
    contour_params["field"] = "braid";
    
    double iso_vals[2] = {0.2, 0.4};
    contour_params["iso_values"].set(iso_vals,2);

    // declare a scene to render the pipeline result

    Node &add_act2 = actions.append();
    add_act2["action"] = "add_scenes";
    Node & scenes = add_act2["scenes"];

    // add a scene (s1) with one pseudocolor plot (p1) that 
    // will render the result of our pipeline (pl1)
    scenes["s1/plots/p1/type"] = "pseudocolor";
    scenes["s1/plots/p1/pipeline"] = "pl1";
    scenes["s1/plots/p1/field"] = "braid";
    // set the output file name (ascent will add ".png")
    scenes["s1/image_name"] = "out_pipeline_ex1_contour";

    // print our full actions tree
    std::cout << actions.to_yaml() << std::endl;

    // execute the actions
    a.execute(actions);

    a.close();
}

Python


import conduit
import conduit.blueprint
import ascent
import numpy as np


mesh = conduit.Node()
conduit.blueprint.mesh.examples.braid("hexs",
                                      25,
                                      25,
                                      25,
                                      mesh)

# Use Ascent to calculate and render contours
a = ascent.Ascent()
a.open()

# publish our mesh to ascent
a.publish(mesh);

# setup actions
actions = conduit.Node()
add_act = actions.append()
add_act["action"] = "add_pipelines"
pipelines = add_act["pipelines"]

# create a  pipeline (pl1) with a contour filter (f1)
pipelines["pl1/f1/type"] = "contour"

# extract contours where braid variable
# equals 0.2 and 0.4
contour_params = pipelines["pl1/f1/params"]
contour_params["field"] = "braid"
iso_vals = np.array([0.2, 0.4],dtype=np.float32)
contour_params["iso_values"].set(iso_vals)

# declare a scene to render the pipeline result

add_act2 = actions.append()
add_act2["action"] = "add_scenes"
scenes = add_act2["scenes"]

# add a scene (s1) with one pseudocolor plot (p1) that 
# will render the result of our pipeline (pl1)
scenes["s1/plots/p1/type"] = "pseudocolor"
scenes["s1/plots/p1/pipeline"] = "pl1"
scenes["s1/plots/p1/field"] = "braid"
# set the output file name (ascent will add ".png")
scenes["s1/image_name"] = "out_pipeline_ex1_contour"

# print our full actions tree
print(actions.to_yaml())

# execute the actions
a.execute(actions)

a.close()
_images/out_pipeline_ex1_contour.png

Fig. 38 Render of contour pipeline result

Combining threshold and clip transforms

C++

#include <iostream>
#include "ascent.hpp"
#include "conduit_blueprint.hpp"

using namespace ascent;
using namespace conduit;

int main(int argc, char **argv)
{
    //create example mesh using the conduit blueprint braid helper
    
    Node mesh;
    conduit::blueprint::mesh::examples::braid("hexs",
                                              25,
                                              25,
                                              25,
                                              mesh);

    // Use Ascent to calculate and render contours

    Ascent a;

    // open ascent
    a.open();

    // publish mesh to ascent
    a.publish(mesh);

    // setup actions
    Node actions;
    Node &add_act = actions.append();
    add_act["action"] = "add_pipelines";
    Node &pipelines = add_act["pipelines"];

    // create a  pipeline (pl1) with a contour filter (f1)
    pipelines["pl1/f1/type"] = "contour";

    // extract contours where braid variable
    // equals 0.2 and 0.4
    Node &contour_params = pipelines["pl1/f1/params"];
    contour_params["field"] = "braid";
    
    double iso_vals[2] = {0.2, 0.4};
    contour_params["iso_values"].set(iso_vals,2);

    // declare a scene to render the pipeline result

    Node &add_act2 = actions.append();
    add_act2["action"] = "add_scenes";
    Node & scenes = add_act2["scenes"];

    // add a scene (s1) with one pseudocolor plot (p1) that 
    // will render the result of our pipeline (pl1)
    scenes["s1/plots/p1/type"] = "pseudocolor";
    scenes["s1/plots/p1/pipeline"] = "pl1";
    scenes["s1/plots/p1/field"] = "braid";
    // set the output file name (ascent will add ".png")
    scenes["s1/image_name"] = "out_pipeline_ex1_contour";

    // print our full actions tree
    std::cout << actions.to_yaml() << std::endl;

    // execute the actions
    a.execute(actions);

    a.close();
}

Python


import conduit
import conduit.blueprint
import ascent
import numpy as np


mesh = conduit.Node()
conduit.blueprint.mesh.examples.braid("hexs",
                                      25,
                                      25,
                                      25,
                                      mesh)

# Use Ascent to calculate and render contours
a = ascent.Ascent()
a.open()

# publish our mesh to ascent
a.publish(mesh);

# setup actions
actions = conduit.Node()
add_act = actions.append()
add_act["action"] = "add_pipelines"
pipelines = add_act["pipelines"]

# create a  pipeline (pl1) with a contour filter (f1)
pipelines["pl1/f1/type"] = "contour"

# extract contours where braid variable
# equals 0.2 and 0.4
contour_params = pipelines["pl1/f1/params"]
contour_params["field"] = "braid"
iso_vals = np.array([0.2, 0.4],dtype=np.float32)
contour_params["iso_values"].set(iso_vals)

# declare a scene to render the pipeline result

add_act2 = actions.append()
add_act2["action"] = "add_scenes"
scenes = add_act2["scenes"]

# add a scene (s1) with one pseudocolor plot (p1) that 
# will render the result of our pipeline (pl1)
scenes["s1/plots/p1/type"] = "pseudocolor"
scenes["s1/plots/p1/pipeline"] = "pl1"
scenes["s1/plots/p1/field"] = "braid"
# set the output file name (ascent will add ".png")
scenes["s1/image_name"] = "out_pipeline_ex1_contour"

# print our full actions tree
print(actions.to_yaml())

# execute the actions
a.execute(actions)

a.close()
_images/out_pipeline_ex2_thresh_clip.png

Fig. 39 Render of threshold and clip pipeline result

Creating and rendering the multiple pipelines

C++

#include <iostream>
#include "ascent.hpp"
#include "conduit_blueprint.hpp"

using namespace ascent;
using namespace conduit;

int main(int argc, char **argv)
{
    //create example mesh using the conduit blueprint braid helper
    
    Node mesh;
    conduit::blueprint::mesh::examples::braid("hexs",
                                              25,
                                              25,
                                              25,
                                              mesh);

    // Use Ascent to calculate and render contours

    Ascent a;

    // open ascent
    a.open();

    // publish mesh to ascent
    a.publish(mesh);

    // setup actions
    Node actions;
    Node &add_act = actions.append();
    add_act["action"] = "add_pipelines";
    Node &pipelines = add_act["pipelines"];

    // create a  pipeline (pl1) with a contour filter (f1)
    pipelines["pl1/f1/type"] = "contour";

    // extract contours where braid variable
    // equals 0.2 and 0.4
    Node &contour_params = pipelines["pl1/f1/params"];
    contour_params["field"] = "braid";
    
    double iso_vals[2] = {0.2, 0.4};
    contour_params["iso_values"].set(iso_vals,2);

    // declare a scene to render the pipeline result

    Node &add_act2 = actions.append();
    add_act2["action"] = "add_scenes";
    Node & scenes = add_act2["scenes"];

    // add a scene (s1) with one pseudocolor plot (p1) that 
    // will render the result of our pipeline (pl1)
    scenes["s1/plots/p1/type"] = "pseudocolor";
    scenes["s1/plots/p1/pipeline"] = "pl1";
    scenes["s1/plots/p1/field"] = "braid";
    // set the output file name (ascent will add ".png")
    scenes["s1/image_name"] = "out_pipeline_ex1_contour";

    // print our full actions tree
    std::cout << actions.to_yaml() << std::endl;

    // execute the actions
    a.execute(actions);

    a.close();
}

Python


import conduit
import conduit.blueprint
import ascent
import numpy as np


mesh = conduit.Node()
conduit.blueprint.mesh.examples.braid("hexs",
                                      25,
                                      25,
                                      25,
                                      mesh)

# Use Ascent to calculate and render contours
a = ascent.Ascent()
a.open()

# publish our mesh to ascent
a.publish(mesh);

# setup actions
actions = conduit.Node()
add_act = actions.append()
add_act["action"] = "add_pipelines"
pipelines = add_act["pipelines"]

# create a  pipeline (pl1) with a contour filter (f1)
pipelines["pl1/f1/type"] = "contour"

# extract contours where braid variable
# equals 0.2 and 0.4
contour_params = pipelines["pl1/f1/params"]
contour_params["field"] = "braid"
iso_vals = np.array([0.2, 0.4],dtype=np.float32)
contour_params["iso_values"].set(iso_vals)

# declare a scene to render the pipeline result

add_act2 = actions.append()
add_act2["action"] = "add_scenes"
scenes = add_act2["scenes"]

# add a scene (s1) with one pseudocolor plot (p1) that 
# will render the result of our pipeline (pl1)
scenes["s1/plots/p1/type"] = "pseudocolor"
scenes["s1/plots/p1/pipeline"] = "pl1"
scenes["s1/plots/p1/field"] = "braid"
# set the output file name (ascent will add ".png")
scenes["s1/image_name"] = "out_pipeline_ex1_contour"

# print our full actions tree
print(actions.to_yaml())

# execute the actions
a.execute(actions)

a.close()
_images/out_pipeline_ex3_two_plots.png

Fig. 40 Render of multiple pipeline results