Merge pull request #3 from raph080/to-hdxTaskController

To hdx task controller and hydra 2.0

BUILDING.md

@@ -0,0 +1,90 @@
+# Building
+
+## Tested platforms
+
+ImGUi Hydra has been developed on MacOS Sonora 14.5 (Macbook Air 2022 - M2).
+
+## Dependencies
+
+Required:
+* gcc compiler
+* [cmake v3.27](https://cmake.org/) or newer
+* [OpenUSD v24.08](https://github.com/PixarAnimationStudios/OpenUSD) or newer
+
+Embedded:
+* [glew](https://github.com/Perlmint/glew-cmake)
+* [glfw v3.4](https://github.com/glfw/glfw)
+* [imgui v1.90.9](https://github.com/ocornut/imgui)
+* [ImGuizmo v1.83](https://github.com/CedricGuillemet/ImGuizmo)
+* [ImGuiFileDialog v0.6.7](https://github.com/aiekick/ImGuiFileDialog)
+* [ImGuiColorTextEdit](https://github.com/BalazsJako/ImGuiColorTextEdit)
+
+## Getting Started
+
+### Install dependencies
+
+Make sure gcc and cmake are installed
+
+```bash
+gcc --version
+cmake --version
+```
+If some version and info are printed after running the previous commands, gcc and cmake are installed. If you get `command not found` error, please be sure to install them first.
+
+### Download OpenUSD
+
+The easy way to get a pre-built version of USD is to download the one from the [Nvidia website](https://developer.nvidia.com/usd).
+
+To build USD manually, go to the [OpenUSD release page](https://github.com/PixarAnimationStudios/OpenUSD/releases), download the last release available and build it (build info in the OpenUSD [README.md](https://github.com/PixarAnimationStudios/OpenUSD/blob/release/README.md)).
+
+Don't forget to add the --embree flag to the build command if you wish to have access to the Embree renderer from ImGui Hydra Editor.
+![embree enabled in ImGui Hydra Editor](resources/storm_embree.png)
+
+```bash
+python3 USD/build_scripts/build_usd.py --embree /path/to/install
+```
+
+### Clone ImGuiHydraEditor
+
+Clone the git project using the following command:
+
+```bash
+git clone --recurse-submodules https://github.com/raph080/ImGuiHydraEditor.git
+```
+
+The recursive flag will automatically include the following projects: glew, glfw, imgui, ImGuiColorTextEdit, ImGuiFileDialog, ImGuizmo
+
+### Build ImGuiHydraEditor
+
+Within the cloned ImGuiHydraEditor, create a build folder and run cmake from this newly created folder by specifying the root path to OpenUSD build:
+
+```bash
+mkdir build
+cd build
+cmake -Dpxr_DIR=/path/to/OpenUSD/build/folder -DCMAKE_INSTALL_PREFIX=/path/to/install/folder ..
+make
+make install
+```
+
+### Run ImGuiHydraEditor
+
+if everything went well, 3 new folders are created in your `/path/to/install/folder`: `bin`, `include` and `lib`.
+
+You can then run the ImGuiHydraEditor application as follow:
+
+Linux:
+```bash
+export LD_LIBRARY_PATH=/path/to/OpenUSD/build/folder/lib:/path/to/OpenUSD/build/folder/lib64:$LD_LIBRARY_PATH
+./ImGuiHydraEditor
+```
+
+MacOS:
+```bash
+export DYLD_LIBRARY_PATH=/path/to/OpenUSD/build/folder/lib:$DYLD_LIBRARY_PATH
+./ImGuiHydraEditor
+```
+
+You can optionally load a USD file directly using the following command:
+```bash
+./ImGuiHydraEditor /input/file.usd
+```

CMakeLists.txt

@@ -8,6 +8,7 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 find_package(pxr REQUIRED)
+find_package(OpenGL REQUIRED)
 
 add_subdirectory(vendors)
 

README.md

@@ -1,104 +1,82 @@
 # ImGui Hydra Editor
 
-ImGui Hydra Editor is a USD editor written in c++ with the ImGui and OpenUSD frameworks.
+ImGui Hydra Editor is a Hydra editor written in c++ with the ImGui and OpenUSD frameworks.
 
 ![UI preview of ImGui Hydra Editor](resources/preview.png)
 
-This project acts as a playground for USD, and most particularly Hydra. Therefore, the structure of the application remains simple and not over-engineered.
+This project acts as a playground for USD, and most particularly Hydra 2.0. Therefore, the structure of the application remains simple and contains out of the box examples.
 
-## Supported platforms
+## Building
 
-ImGui Hydra Editor was primarily developed on MacOS (Ventura 13.6) but was also built and tested on Linux (Centos 7).
+To build ImGui Hydra Editor, see [BUILDING.md](BUILDING.md) instructions.
 
-## Dependencies
+## Overview
 
-Required:
-* gcc compiler
-* [cmake v3.27](https://cmake.org/) or newer
-* [OpenUSD v23.08](https://github.com/PixarAnimationStudios/OpenUSD) or newer
+ImGui Hydra Editor is a tool that processes data using the Hydra 2.0 Framework. Every view from the tool has access to read, insert and author the current state
+of Hydra data.
 
-Embedded:
-* [glew](https://github.com/Perlmint/glew-cmake)
-* [glfw v3.3.8](https://github.com/glfw/glfw)
-* [imgui v1.89.9](https://github.com/ocornut/imgui)
-* [ImGuizmo v1.83](https://github.com/CedricGuillemet/ImGuizmo)
-* [ImGuiFileDialog v0.6.5](https://github.com/aiekick/ImGuiFileDialog)
-* [ImGuiColorTextEdit](https://github.com/BalazsJako/ImGuiColorTextEdit)
+![Views that interact with Hydra data](resources/views_hydra_data.png)
 
-## Documentation
+### Usd Session Layer
 
-For more information about the code, please check the header files.
+From the Usd Session Layer view, the user can type a stage from scratch, add some predefined USD Prim (camera, cube, sphere, ...) or load a USD file and author it. The Usd Session Layer then converts the USD Prims to Hydra Prims and inserts them to Hydra data.
 
-## Getting Started
+### Outliner
 
-### Install dependencies
+The Outliner view browses all Hydra prims from Hydra data and displays them in a tree view.
 
-Make sure gcc and cmake are installed
+### Viewport
 
-```bash
-gcc --version
-cmake --version
-```
-If some version and info are printed after running the previous commands, gcc and cmake are installed. If you get `command not found` error, please be sure to install them first.
+The viewport view authors the transforms (translate, rotate, scale) of Hydra Prims. It also creates and inserts a grid to Hydra data.
 
-### Download OpenUSD
+### Editor
 
-The easy way to get a pre-built version of USD is to download the one from the [Nvidia website](https://developer.nvidia.com/usd).
+The Editor view allows the user to author the display color of the selected Hydra Prim. The view also displays all the Hydra attributes from the selection.
 
-To build USD manually, go to the [OpenUSD release page](https://github.com/PixarAnimationStudios/OpenUSD/releases), download the last release available and build it (build info in the OpenUSD [README.md](https://github.com/PixarAnimationStudios/OpenUSD/blob/release/README.md)).
+### Engine
 
-Don't forget to add the --embree flag to the build command if you wish to have access to the Embree renderer from ImGui Hydra Editor.
-![embree enabled in ImGui Hydra Editor](resources/storm_embree.png)
+The Engine consumes Hydra data with all modifications from the views and generates an image from it.
 
-```bash
-python3 USD/build_scripts/build_usd.py --embree /path/to/install
-```
 
+## Scenes Indices
 
-### Clone ImGuiHydraEditor
+ImGui Hydra Editor implements main concepts of Hydra 2.0 framework out of the box, such as:
+* inserting data using [HdSceneIndexBase](https://openusd.org/release/api/class_hd_scene_index_base.html) and UsdImagingStageSceneIndex.
+* authoring data via [HdSingleInputFilteringSceneIndexBase](https://openusd.org/release/api/class_hd_single_input_filtering_scene_index_base.html)
+* merging multiple data source using [HdMergingSceneIndex](https://openusd.org/release/api/class_hd_merging_scene_index.html)
 
-Clone the git project using the following command:
 
-```bash
-git clone --recurse-submodules https://github.com/raph080/ImGuiHydraEditor.git
-```
+The views in ImGui Hydra Editor make use of those various types of scene index in order to create the final data to feed to Hydra (Hydra data).
 
-The recursive flag will automatically include the following projects: glew, glfw, imgui, ImGuiColorTextEdit, ImGuiFileDialog, ImGuizmo
+![Scene indices Schema](resources/scene_indices_schema.png)
 
-### Build ImGuiHydraEditor
+### HdSceneIndexBase
 
-Within the cloned ImGuiHydraEditor, create a build folder and run cmake from this newly created folder by specifying the root path to OpenUSD build:
+HdSceneIndexBase is used to insert data to Hydra data.
 
-```bash
-mkdir build
-cd build
-cmake -Dpxr_DIR=/path/to/OpenUSD/build/folder -DCMAKE_INSTALL_PREFIX=/path/to/install/folder ..
-make
-make install
-```
+Examples are:
+* UsdImagingStageSceneIndex: used by Usd Session Layer to convert USD data to Hydra data.
+* GridSceneIndex: used by Viewport to create and insert a grid to Hydra data.
 
-### Run ImGuiHydraEditor
-
-if everything went well, 3 new folders are created in your `/path/to/install/folder`: `bin`, `include` and `lib`.
+### HdSingleInputFilteringSceneIndexBase
 
-You can then run the ImGuiHydraEditor application as follow:
+HdSingleInputFilteringSceneIndexBase is used to filter Hydra data in order to author the Hydra Prim states.
 
-Linux:
-```bash
-export LD_LIBRARY_PATH=/path/to/OpenUSD/build/folder/lib:/path/to/OpenUSD/build/folder/lib64:$LD_LIBRARY_PATH
-./ImGuiHydraEditor
-```
+Examples are:
+* XformFilterSceneIndex: used by Viewport to author the xform of Hydra Prims.
+* ColorFilterSceneIndex: used by Editor to author the display color of Hydra Prims.
 
-MacOS:
-```bash
-export DYLD_LIBRARY_PATH=/path/to/OpenUSD/build/folder/lib:$DYLD_LIBRARY_PATH
-./ImGuiHydraEditor
-```
+### HdMergingSceneIndex
 
-You can optionally load a USD file directly using the following command:
-```bash
-./ImGuiHydraEditor /input/file.usd
-```
+HdMergingSceneIndex is used to merge multiple scene indices together.
+
+Examples are:
+* SceneIndexBases: merge multiple inputs (USD prim & grid) to a single output.
+* FinalSceneIndex: always contains the scene index with the latest changes.
+
+## Rendering
+
+In order for the render engine to be more flexible, the render is performed using HdRenderIndex, HdEngine and HdxTaskController. See the code for more information.
 
 ## Viewport navigation
 
@@ -136,7 +114,7 @@ Once the custom render delegates are build, don't forget to set the `PXR_PLUGINP
 ## And more
 
 Explore the menu bars of the application and viewports, you may find useful fonctionalities such as:
-* Create new objects in the scenes (Camera, Cube, ...)
+* Create new USD objects in the scenes (Camera, Cube, ...)
 * Create new views in the main window
 * Switch the active camera to the viewport
 * Show/Hide the grid
@@ -158,12 +136,4 @@ There is currently some limitations
 * Instanceable cannot be selected (if so selection will switch to parent)
 * No Undo
 * Grid is on a separate layer at the back
-* Does not keep multiple instances of same view when relaunched
-
-## Next steps
-
-Here are the next steps that are planned in order to improve the tool and discover more about Hydra:
-* Switch from UsdImagingGLEngine to HdEngine or HdxTaskController
-  * Allows multiple scene delegates
-  * Add the grid dynamically to the RenderIndex
-  * Abstract the Model to Hydra Objects (not USD object anymore)
+* Does not keep multiple instances of same view when relaunched