add 2d camera mode controls for rendering and project_2d (#1484)

* add 2d camera mode for rendering and project_2d

* update info with 2d cam

* changelog

Author: cyrush

CHANGELOG.md

@@ -4,10 +4,10 @@ Notable changes to Ascent are documented in this file. This changelog started on
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project aspires to adhere to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased 
+## Unreleased
 ### Preferred dependency versions for ascent@develop
 - [email protected]
-- [email protected] (requires [patch 1](https://github.com/Alpine-DAV/ascent/blob/0aef6cffd522be7419651e6adf586f9a553297d0/scripts/build_ascent/2024_05_03_vtkm-mr3215-ext-geom-fix.patch) 
+- [email protected] (requires [patch 1](https://github.com/Alpine-DAV/ascent/blob/0aef6cffd522be7419651e6adf586f9a553297d0/scripts/build_ascent/2024_05_03_vtkm-mr3215-ext-geom-fix.patch)
                         [patch 2](https://github.com/Alpine-DAV/ascent/blob/develop/scripts/build_ascent/2024_07_02_vtkm-mr3246-raysubset_bugfix.patch) )
 - [email protected]
 - [email protected]
@@ -31,11 +31,12 @@ and this project aspires to adhere to [Semantic Versioning](https://semver.org/s
 - Added `fields` option to the project 2d to support scalar rendering of specific fields.
 - Added `dataset_bounds` option to the project 2d, which can be used instead of a full 3D camera specification
 - Added support for triggers to execute actions from multiple files via an `actions_files` option that takes a list of actions files.
-- Added an `external_surfaces` transform filter, that can be used to reduce memory requirements in pipelines where you plan to only process the external faces of a data set. 
+- Added an `external_surfaces` transform filter, that can be used to reduce memory requirements in pipelines where you plan to only process the external faces of a data set.
 - Added a `declare_fields` action, that allows users to explicitly list the fields to return for field filtering. This option avoids complex field parsing logic.
+- Added a 2d camera mode (`camera/2d: [left, right, bottom, top]`) to scene render cameras and the `project_2d` (scalar rendering) filter cameras.
 
 ### Changed
-- Changed the replay utility's binary names such that `replay_ser` is now `ascent_replay` and `raplay_mpi` is now `ascent_replay_mpi`. This will help prevent potential name collisions with other tools that also have replay utilities. 
+- Changed the replay utility's binary names such that `replay_ser` is now `ascent_replay` and `raplay_mpi` is now `ascent_replay_mpi`. This will help prevent potential name collisions with other tools that also have replay utilities.
 
 ### Fixed
 - Resolved a few cases where MPI_COMM_WORLD was used instead instead of the selected MPI communicator.
@@ -75,7 +76,7 @@ and this project aspires to adhere to [Semantic Versioning](https://semver.org/s
 ### Changed
 - Changed the Data Binning filter to accept a `reduction_field` parameter (instead of `var`), and similarly the axis parameters to take `field` (instead of `var`).  The `var` style parameters are still accepted, but deprecated and will be removed in a future release.
 - Changed the Streamline and WarpXStreamline filters to apply the VTK-m Tube filter to their outputs, allowing for the results to be rendered.
-- Updated CMake Python build infrastructure to use 
+- Updated CMake Python build infrastructure to use
 
 ### Fixed
 - Various small bug fixes
@@ -128,12 +129,12 @@ and this project aspires to adhere to [Semantic Versioning](https://semver.org/s
 - Added extract `flatten` from Conduit Blueprint
 - Added Log base 10 filter. Filter type is `log10`
 - Added Log base 2 filter. Filter type is `log2`
-- Added Feature Map in the docs. Detailing Devil Ray and VTKh features 
+- Added Feature Map in the docs. Detailing Devil Ray and VTKh features
 - Added `scripts/build_ascent/build_ascent.sh` a script that demonstrates how to manually build Ascent and its main dependencies
 - Added ability to override dimensions for the rendered bounding box around a dataset
 - Added CMake option `ENABLE_HIDDEN_VISIBILITY` (default=ON), which controls if hidden visibility is used for private symbols
 - Added documentation for how to use ROCm's rocprof profiler for GPUs with Ascent
-- Added support for Caliper performance annotations 
+- Added support for Caliper performance annotations
 - Added automatic slice filter that evaluates a number of slices and outputs the one with the highest entropy
 
 ### Changed
@@ -157,15 +158,15 @@ and this project aspires to adhere to [Semantic Versioning](https://semver.org/s
 - Added OCCA Derived Field Generation support
 - Added more math expressions
 - Added a time expression
-- Added Cinema rendering support for Devil Ray 
-- Added `streamline` and `particle_advection` transforms 
+- Added Cinema rendering support for Devil Ray
+- Added `streamline` and `particle_advection` transforms
 - Added history gradient expressions
 - Added the ability save named sessions
 - Added new options to specify Cinema rendering parameters
 - Added the ability save subsets of expression results to session files
 - Added the ability to add comments to PNG files that Ascent creates
 - Added timings out control option to Ascent (and Flow)
-- Added support to render Polygonal nd Polyhedral Meshes 
+- Added support to render Polygonal nd Polyhedral Meshes
 - Added option to turn of world annotations
 - Added FIDES Support
 

src/libs/ascent/runtimes/flow_filters/ascent_runtime_conduit_to_vtkm_parsing.cpp

@@ -87,14 +87,33 @@ parse_image_dims(const conduit::Node &node, int &width, int &height)
 
 }
 
+
 //-----------------------------------------------------------------------------
 void
 parse_camera(const conduit::Node camera_node, vtkm::rendering::Camera &camera)
 {
   typedef vtkm::Vec<vtkm::Float32,3> vtkmVec3f;
+
   //
   // Get the optional camera parameters
   //
+
+  // check for 2d mode first
+  if(camera_node.has_child("2d"))
+  {
+    // camera:
+    //  2d: [l,r,b,t]
+    camera.SetModeTo2D();
+    conduit::Node n;
+    camera_node["2d"].to_float64_array(n);
+    const float64 *view_vals = n.as_float64_ptr();
+
+    camera.SetViewRange2D(view_vals[0],
+                          view_vals[1],
+                          view_vals[2],
+                          view_vals[3]);
+  }
+
   if(camera_node.has_child("look_at"))
   {
       conduit::Node n;
@@ -248,8 +267,8 @@ parse_color_table(const conduit::Node &color_table_node)
     }
     else if (control_points_node.dtype().is_object())
     {
-        if (control_points_node.has_child("r") && 
-            control_points_node.has_child("g") && 
+        if (control_points_node.has_child("r") &&
+            control_points_node.has_child("g") &&
             control_points_node.has_child("b"))
         {
             clear = true;