Adding Hydra Generative Procedural Example of a simple Triangle

Signed-off-by: Seb Schmidt <[email protected]>

README.md

@@ -26,6 +26,7 @@ Huge thanks to Pixar's USD team for providing a highly extensible platform!
 - [usdTriImagingHd2](./src/usdTriImagingHd2): A *Hydra 2 only* prim adapter which images the **Triangle** prim type. [*]
 - [usdTriFileFormat](./src/usdTriFileFormat): A file format plugin which authors a triangular mesh for a `.triangle` payload.
 - [hdTri](./src/hdTri): A hydra renderer plugin which images a triangle (in the most direct sense).
+- [hdGpTri](./src/hdGpTri): A generative procedural plugin which creates a triangle (in the most direct sense).
 - [usdviewTri](./src/usdviewTri): An usdview plugin providing a menu command to define child Triangle prim(s) under selected paths.
 
 [*] We deliberatly split the Hydra 1 & 2 Triangle Prim Adapters into two plugins/sources to outline the differences

src/CMakeLists.txt

@@ -16,6 +16,7 @@ endif()
 
 add_subdirectory(usdTriFileFormat)
 add_subdirectory(hdTri)
+add_subdirectory(hdGpTri)
 
 # Install top-level plugInfo for including per-library plugInfo(s).
 install(

src/hdGpTri/CMakeLists.txt

@@ -0,0 +1,25 @@
+usd_plugin(hdGpTri
+
+    PUBLIC_HEADERS_INSTALL_PREFIX
+        ${ORGANIZATION}
+
+    PYTHON_INSTALL_PREFIX
+        ${ORGANIZATION}
+
+    LIBRARIES
+        js
+        plug
+        tf
+        sdf
+        vt
+        gf
+        hdGp
+        arch
+
+    CPPFILES
+        triGenerative.cpp
+        debugCodes.cpp
+
+    RESOURCE_FILES
+        plugInfo.json
+)

src/hdGpTri/debugCodes.cpp

@@ -0,0 +1,18 @@
+//
+// Copyright © 2024 Weta Digital Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+#include "debugCodes.h"
+#include "pxr/base/tf/debug.h"
+#include <pxr/base/tf/registryManager.h>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+TF_REGISTRY_FUNCTION(TfDebug)
+{
+    TF_DEBUG_ENVIRONMENT_SYMBOL(
+        USDTRI_GENERATIVE, "Debug symbol for the usdTri GenerativeProcedural.");
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE

src/hdGpTri/debugCodes.h

@@ -0,0 +1,15 @@
+//
+// Copyright © 2024 Weta Digital Limited
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+#pragma once
+
+#include <pxr/pxr.h>
+#include <pxr/base/tf/debug.h>
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+TF_DEBUG_CODES(USDTRI_GENERATIVE);
+
+PXR_NAMESPACE_CLOSE_SCOPE

src/hdGpTri/plugInfo.json

@@ -0,0 +1,22 @@
+{
+    "Plugins": [
+        {
+            "Info": {
+                "Types": {
+                    "TriProceduralPlugin": {
+                        "bases": [
+                            "HdGpGenerativeProceduralPlugin"
+                        ],
+                        "displayName": "triangle",
+                        "priority" : 0
+                    }
+                }
+            },
+            "LibraryPath": "../../hdGpTri.so",
+            "Name": "hdGpTri",
+            "ResourcePath": "resources",
+            "Root": "..",
+            "Type": "library"
+        }
+    ]
+}

src/hdGpTri/scenes/triangle.usda

@@ -0,0 +1,42 @@
+#usda 1.0
+
+
+def Scope "World"
+{
+    def GenerativeProcedural "myGenerativeProc" (
+        prepend apiSchemas = ["HydraGenerativeProceduralAPI"]
+    )
+    {
+        token primvars:hdGp:proceduralType = "triangle"
+        double primvars:sideLength = 1.0
+    }
+
+    def Scope "leaf_transformed"
+    {
+
+        def GenerativeProcedural "myGenerativeProcTransformed" (
+            prepend apiSchemas = ["HydraGenerativeProceduralAPI"]
+        )
+        {
+            token primvars:hdGp:proceduralType = "triangle"
+            double primvars:sideLength = 1.0
+
+            matrix4d xformOp:transform:transform1 = ( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (15, 15, 15, 1) )
+            uniform token[] xformOpOrder = ["xformOp:transform:transform1"]
+        }
+    }
+    def Xform "transformed"
+    {
+        matrix4d xformOp:transform:transform1 = ( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (15, 15, 15, 1) )
+        uniform token[] xformOpOrder = ["xformOp:transform:transform1"]
+
+        def GenerativeProcedural "myGenerativeProcTransformed" (
+            prepend apiSchemas = ["HydraGenerativeProceduralAPI"]
+        )
+        {
+            token primvars:hdGp:proceduralType = "triangle"
+            double primvars:sideLength = 1.0
+
+        }
+    }
+}

src/hdGpTri/scenes/triangleAnimated.usda

@@ -0,0 +1,23 @@
+#usda 1.0
+(
+    startFrame = 1
+    endFrame = 10
+)
+
+def Scope "World"
+{
+    def GenerativeProcedural "myGenerativeProcAnimated" (
+        prepend apiSchemas = ["HydraGenerativeProceduralAPI"]
+    )
+    {
+        token primvars:hdGp:proceduralType = "triangle"
+        double primvars:sideLength = 1.0
+        double primvars:sideLength.timeSamples = {
+            1: 1,
+            10: 10
+        }
+
+        matrix4d xformOp:transform:transform1 = ( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (30, 30, 30, 1) )
+        uniform token[] xformOpOrder = ["xformOp:transform:transform1"]
+    }
+}