Support "vertex" UV coordinates on curves in the render delegate

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Feature
+- [usd#1435](https://github.com/Autodesk/arnold-usd/issues/1435) - Support "vertex" UV coordinates on Curves in the render delegate
+- [usd#1579](https://github.com/Autodesk/arnold-usd/issues/1579) - Curves without any width should render with a default value
+
 ### Bug fixes
 - [usd#1567](https://github.com/Autodesk/arnold-usd/issues/1567) - Fix metallic attribute in UsdPreviewSurface in the render delegate
 - [usd#1550](https://github.com/Autodesk/arnold-usd/issues/1550) - UsdPrimvarReader_float2 returning "st" not working in the usd procedural

libs/render_delegate/basis_curves.cpp

@@ -181,8 +181,33 @@ void HdArnoldBasisCurves::Sync(
                 } else {
                     ArnoldUsdCurvesData::SetRadiusFromValue(GetArnoldNode(), desc.value);
                 }
-                // For constant and
-            } else if (desc.interpolation == HdInterpolationConstant) {
+                continue;
+            }
+            if (primvar.first == str::t_uv || primvar.first == str::t_st) {
+                // This is either a VtVec2fArray or VtVec3fArray (in Solaris).
+                if (desc.value.IsHolding<VtVec2fArray>()) {
+                    const auto& v = desc.value.UncheckedGet<VtVec2fArray>();
+                    AiNodeSetArray(
+                        GetArnoldNode(), str::uvs, AiArrayConvert(v.size(), 1, AI_TYPE_VECTOR2, v.data()));
+                    continue;
+                }
+                if (desc.value.IsHolding<VtVec3fArray>()) {
+                    const auto& v = desc.value.UncheckedGet<VtVec3fArray>();
+                    auto* arr = AiArrayAllocate(v.size(), 1, AI_TYPE_VECTOR2);
+                    if (!v.empty()) {
+                        std::transform(
+                            v.begin(), v.end(), static_cast<GfVec2f*>(AiArrayMap(arr)),
+                            [](const GfVec3f& in) -> GfVec2f {
+                                return {in[0], in[1]};
+                            });
+                        AiArrayUnmap(arr);
+                    }
+                    AiNodeSetArray(GetArnoldNode(), str::uvs, arr);
+                    continue;
+                } 
+            }
+
+            if (desc.interpolation == HdInterpolationConstant) {
                 // We skip reading the basis for now as it would require remapping the vertices, widths and
                 // all the primvars.
                 if (primvar.first != _tokens->basis) {
@@ -191,31 +216,7 @@ void HdArnoldBasisCurves::Sync(
                         nullptr);
                 }
             } else if (desc.interpolation == HdInterpolationUniform) {
-                if (primvar.first == str::t_uv || primvar.first == str::t_st) {
-                    // This is either a VtVec2fArray or VtVec3fArray (in Solaris).
-                    if (desc.value.IsHolding<VtVec2fArray>()) {
-                        const auto& v = desc.value.UncheckedGet<VtVec2fArray>();
-                        AiNodeSetArray(
-                            GetArnoldNode(), str::uvs, AiArrayConvert(v.size(), 1, AI_TYPE_VECTOR2, v.data()));
-                    } else if (desc.value.IsHolding<VtVec3fArray>()) {
-                        const auto& v = desc.value.UncheckedGet<VtVec3fArray>();
-                        auto* arr = AiArrayAllocate(v.size(), 1, AI_TYPE_VECTOR2);
-                        if (!v.empty()) {
-                            std::transform(
-                                v.begin(), v.end(), static_cast<GfVec2f*>(AiArrayMap(arr)),
-                                [](const GfVec3f& in) -> GfVec2f {
-                                    return {in[0], in[1]};
-                                });
-                            AiArrayUnmap(arr);
-                        }
-                        AiNodeSetArray(GetArnoldNode(), str::uvs, arr);
-                    } else {
-                        // If it's an unsupported type, just set it as user data.
-                        HdArnoldSetUniformPrimvar(GetArnoldNode(), primvar.first, desc.role, desc.value);
-                    }
-                } else {
-                    HdArnoldSetUniformPrimvar(GetArnoldNode(), primvar.first, desc.role, desc.value);
-                }
+                HdArnoldSetUniformPrimvar(GetArnoldNode(), primvar.first, desc.role, desc.value);                
             } else if (desc.interpolation == HdInterpolationVertex || desc.interpolation == HdInterpolationVarying) {
                 if (primvar.first == HdTokens->points) {
                     HdArnoldSetPositionFromValue(GetArnoldNode(), str::curves, desc.value);
@@ -233,8 +234,6 @@ void HdArnoldBasisCurves::Sync(
                     }
                     HdArnoldSetVertexPrimvar(GetArnoldNode(), primvar.first, desc.role, value);
                 }
-            } else if (desc.interpolation == HdInterpolationVarying) {
-                HdArnoldSetVertexPrimvar(GetArnoldNode(), primvar.first, desc.role, desc.value);
             }
         }
         UpdateVisibilityAndSidedness();

libs/render_delegate/utils.cpp

@@ -1729,17 +1729,16 @@ AtArray* HdArnoldGetShidxs(const HdGeomSubsets& subsets, int numFaces, HdArnoldS
 
 bool HdArnoldDeclare(AtNode* node, const TfToken& name, const TfToken& scope, const TfToken& type)
 {
-    if (AiNodeEntryLookUpParameter(AiNodeGetNodeEntry(node), AtString(name.GetText())) != nullptr) {
-        TF_DEBUG(HDARNOLD_PRIMVARS)
-            .Msg(
-                "Unable to translate %s primvar for %s due to a name collision with a built-in parameter",
-                name.GetText(), AiNodeGetName(node));
-        return false;
-    }
     const AtString nameStr{name.GetText()};
-    if (AiNodeLookUpUserParameter(node, nameStr) != nullptr) {
+    // If the attribute already exists (either as a node entry parameter
+    // or as a user data in the node), then we should not call AiNodeDeclare
+    // as it would fail.    
+    if (AiNodeLookUpUserParameter(node, nameStr) ||
+            AiNodeEntryLookUpParameter(AiNodeGetNodeEntry(node), nameStr)) {
         AiNodeResetParameter(node, nameStr);
+        return true;
     }
+
     return AiNodeDeclare(node, nameStr, AtString(TfStringPrintf("%s %s", scope.GetText(), type.GetText()).c_str()));
 }
 

libs/translator/reader/read_geometry.cpp

@@ -480,13 +480,7 @@ void UsdArnoldReadCurves::Read(const UsdPrim &prim, UsdArnoldReaderContext &cont
     staticTime.motionBlur = false;
 
     UsdGeomCurves curves(prim);
-
-    VtValue widthValues;
-    if (!curves.GetWidthsAttr().Get(&widthValues, frame)) {
-        AiMsgWarning("[usd] Skipping curves with empty width %s", prim.GetPath().GetText());
-        return;
-    }
-
+
     AtNode *node = context.CreateArnoldNode("curves", prim.GetPath().GetText());
 
     AtString basis = str::linear;
@@ -516,8 +510,6 @@ void UsdArnoldReadCurves::Read(const UsdPrim &prim, UsdArnoldReaderContext &cont
         }
     }
 
-
-
     AiNodeSetStr(node, str::basis, basis);
 
     // CV counts per curve
@@ -533,16 +525,22 @@ void UsdArnoldReadCurves::Read(const UsdPrim &prim, UsdArnoldReaderContext &cont
     const auto vstep = basis == str::bezier ? 3 : 1;
     const auto vmin = basis == str::linear ? 2 : 4;
     ArnoldUsdCurvesData curvesData(vmin, vstep, vertexCounts);
-
-    TfToken widthInterpolation = curves.GetWidthsInterpolation();
-    if ((widthInterpolation == UsdGeomTokens->vertex || widthInterpolation == UsdGeomTokens->varying) &&
-            basis != str::linear) {
-        // if radius data is per-vertex and the curve is pinned, then don't remap
-        if (!(widthInterpolation == UsdGeomTokens->vertex && isValidPinnedCurve))
-            curvesData.RemapCurvesVertexPrimvar<float, double>(widthValues);
-        curvesData.SetRadiusFromValue(node, widthValues);
+
+    VtValue widthValues;
+    if (curves.GetWidthsAttr().Get(&widthValues, frame)) {
+        TfToken widthInterpolation = curves.GetWidthsInterpolation();
+        if ((widthInterpolation == UsdGeomTokens->vertex || widthInterpolation == UsdGeomTokens->varying) &&
+                basis != str::linear) {
+            // if radius data is per-vertex and the curve is pinned, then don't remap
+            if (!(widthInterpolation == UsdGeomTokens->vertex && isValidPinnedCurve))
+                curvesData.RemapCurvesVertexPrimvar<float, double>(widthValues);
+            curvesData.SetRadiusFromValue(node, widthValues);
+        } else {
+            curvesData.SetRadiusFromValue(node, widthValues);
+        }
     } else {
-        curvesData.SetRadiusFromValue(node, widthValues);
+        // Width isn't defined, we assume a constant width equal to 1
+        AiNodeSetFlt(node, str::radius, 0.5);
     }
 
     ReadMatrix(prim, node, time, context);

testsuite/test_1435/README

@@ -0,0 +1,7 @@
+Curves with per-vertex st coordinates
+
+See #1435
+
+author: sebastien.ortega
+
+PARAMS: {'scene':'test.usda'}

testsuite/test_1435/data/test.usda

@@ -0,0 +1,211 @@
+#usda 1.0
+(
+    doc = """Generated from Composed Stage of root layer 
+"""
+    endTimeCode = 1
+    framesPerSecond = 24
+    metersPerUnit = 1
+    startTimeCode = 1
+    timeCodesPerSecond = 24
+    upAxis = "Y"
+)
+
+def Xform "test" (
+    kind = "component"
+)
+{
+    def BasisCurves "test" (
+        apiSchemas = ["MaterialBindingAPI"]
+    )
+    {
+        uniform token basis = "bezier"
+        int[] curveVertexCounts = [2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2]
+        float3[] extent = [(-5, 0, -5), (5, 1, 3.5779235)]
+        rel material:binding = </materials/shader>
+        point3f[] points = [(-0.86734253, 0, -0.9439319), (-0.86734253, 1, -0.9439319), (5, 0, 0.7396351), (5, 1, 0.7396351), (-2.928457, 0, -2.2366061), (-2.928457, 1, -2.2366061), (-0.9475007, 0, -3.191457), (-0.9475007, 1, -3.191457), (2.1079116, 0, 1.7289146), (2.1079116, 1, 1.7289146), (-3.0919335, 0, 0.07936842), (-3.0919335, 1, 0.07936842), (-5, 0, 1.499233), (-5, 1, 1.499233), (1.4457333, 0, -0.7533004), (1.4457333, 1, -0.7533004), (0.2606192, 0, 0.9491923), (0.2606192, 1, 0.9491923), (1.1564449, 0, -2.8530495), (1.1564449, 1, -2.8530495), (5, 0, -2.212023), (5, 1, -2.212023), (-1.3227377, 0, 2.1443152), (-1.3227377, 1, 2.1443152), (-4.9845285, 0, -1.2268404), (-4.9845285, 1, -1.2268404), (-3.2350502, 0, 3.0137196), (-3.2350502, 1, 3.0137196), (3.179194, 0, -1.9110526), (3.179194, 1, -1.9110526), (3.4112368, 0, 0.16663373), (3.4112368, 1, 0.16663373), (-4.0955606, 0, -4.076156), (-4.0955606, 1, -4.076156), (3.3390605, 0, -4.132369), (3.3390605, 1, -4.132369), (3.6978378, 0, 3.1946297), (3.6978378, 1, 3.1946297), (0.96328783, 0, -5), (0.96328783, 1, -5), (-1.6550982, 0, -5), (-1.6550982, 1, -5), (0.8823204, 0, 3.5779235), (0.8823204, 1, 3.5779235)] (
+            interpolation = "vertex"
+        )
+        string primvars:arnold:mode = "thick" (
+            interpolation = "constant"
+        )
+        texCoord2f[] primvars:st = [(0.41326576, 0.4056068), (0.41326576, 0.4056068), (1, 0.5739635), (1, 0.5739635), (0.2071543, 0.27633938), (0.2071543, 0.27633938), (0.40524995, 0.18085429), (0.40524995, 0.18085429), (0.7107911, 0.67289144), (0.7107911, 0.67289144), (0.19080666, 0.50793684), (0.19080666, 0.50793684), (0, 0.6499233), (0, 0.6499233), (0.6445733, 0.42466995), (0.6445733, 0.42466995), (0.5260619, 0.5949192), (0.5260619, 0.5949192), (0.61564445, 0.21469504), (0.61564445, 0.21469504), (1, 0.2787977), (1, 0.2787977), (0.36772624, 0.7144315), (0.36772624, 0.7144315), (0.0015471459, 0.37731594), (0.0015471459, 0.37731594), (0.17649497, 0.801372), (0.17649497, 0.801372), (0.81791943, 0.30889475), (0.81791943, 0.30889475), (0.84112364, 0.5166634), (0.84112364, 0.5166634), (0.09044395, 0.09238439), (0.09044395, 0.09238439), (0.83390605, 0.0867631), (0.83390605, 0.0867631), (0.8697838, 0.819463), (0.8697838, 0.819463), (0.5963288, 0), (0.5963288, 0), (0.33449015, 0), (0.33449015, 0), (0.58823204, 0.8577924), (0.58823204, 0.8577924)] (
+            interpolation = "vertex"
+        )
+        int[] primvars:st:indices = None
+        uniform token type = "linear"
+        uniform token wrap = "nonperiodic"
+    }
+}
+
+def Scope "materials"
+{
+    def Material "shader"
+    {
+        token outputs:arnold:surface.connect = </materials/shader/standard_surface1.outputs:shader>
+
+        def Shader "standard_surface1"
+        {
+            uniform token info:id = "arnold:standard_surface"
+            string inputs:aov_id1 = ""
+            string inputs:aov_id2 = ""
+            string inputs:aov_id3 = ""
+            string inputs:aov_id4 = ""
+            string inputs:aov_id5 = ""
+            string inputs:aov_id6 = ""
+            string inputs:aov_id7 = ""
+            string inputs:aov_id8 = ""
+            float inputs:base = 1
+            color3f inputs:base_color = (0.8, 0.8, 0.8)
+            color3f inputs:base_color.connect = </materials/shader/checkerboard_good.outputs:rgb>
+            bool inputs:caustics = 0
+            float inputs:coat = 0
+            float inputs:coat_affect_color = 0
+            float inputs:coat_affect_roughness = 0
+            float inputs:coat_anisotropy = 0
+            color3f inputs:coat_color = (1, 1, 1)
+            float inputs:coat_IOR = 1.5
+            vector3f inputs:coat_normal = (0, 0, 0)
+            float inputs:coat_rotation = 0
+            float inputs:coat_roughness = 0.1
+            int inputs:dielectric_priority = 0
+            float inputs:diffuse_roughness = 0
+            float inputs:emission = 0
+            color3f inputs:emission_color = (1, 1, 1)
+            bool inputs:exit_to_background = 0
+            color3f inputs:id1 = (0, 0, 0)
+            color3f inputs:id2 = (0, 0, 0)
+            color3f inputs:id3 = (0, 0, 0)
+            color3f inputs:id4 = (0, 0, 0)
+            color3f inputs:id5 = (0, 0, 0)
+            color3f inputs:id6 = (0, 0, 0)
+            color3f inputs:id7 = (0, 0, 0)
+            color3f inputs:id8 = (0, 0, 0)
+            float inputs:indirect_diffuse = 1
+            float inputs:indirect_specular = 1
+            bool inputs:internal_reflections = 1
+            float inputs:metalness = 0
+            vector3f inputs:normal = (0, 0, 0)
+            color3f inputs:opacity = (1, 1, 1)
+            float inputs:sheen = 0
+            color3f inputs:sheen_color = (1, 1, 1)
+            float inputs:sheen_roughness = 0.3
+            float inputs:specular = 1
+            float inputs:specular_anisotropy = 0
+            color3f inputs:specular_color = (1, 1, 1)
+            float inputs:specular_IOR = 1.5
+            float inputs:specular_rotation = 0
+            float inputs:specular_roughness = 0.2
+            float inputs:subsurface = 0
+            float inputs:subsurface_anisotropy = 0
+            color3f inputs:subsurface_color = (1, 1, 1)
+            color3f inputs:subsurface_radius = (1, 1, 1)
+            float inputs:subsurface_scale = 1
+            token inputs:subsurface_type = "randomwalk"
+            vector3f inputs:tangent = (0, 0, 0)
+            float inputs:thin_film_IOR = 1.5
+            float inputs:thin_film_thickness = 0
+            bool inputs:thin_walled = 0
+            float inputs:transmission = 0
+            color3f inputs:transmission_color = (1, 1, 1)
+            float inputs:transmission_depth = 0
+            float inputs:transmission_dispersion = 0
+            float inputs:transmission_extra_roughness = 0
+            color3f inputs:transmission_scatter = (0, 0, 0)
+            float inputs:transmission_scatter_anisotropy = 0
+            bool inputs:transmit_aovs = 0
+            token outputs:shader
+        }
+
+        def Shader "checkerboard_good"
+        {
+            uniform token info:id = "arnold:checkerboard"
+            color3f inputs:color1 = (1, 1, 1)
+            color3f inputs:color2 = (0, 0, 0)
+            float inputs:contrast = 1
+            float inputs:filter_offset = 0
+            float inputs:filter_strength = 1
+            float inputs:u_frequency = 1
+            float inputs:u_offset = 0
+            string inputs:uvset = ""
+            float inputs:v_frequency = 1.27
+            float inputs:v_offset = 0
+            color3f outputs:rgb
+        }
+    }
+}
+
+def Xform "lights"
+{
+    def DomeLight "domelight1" (
+        apiSchemas = ["HoudiniViewportGuideAPI"]
+    )
+    {
+        custom rel filters
+        float houdini:guidescale = 1
+        uniform bool houdini:inviewermenu = 0
+        color3f inputs:color = (1, 1, 1)
+        float inputs:diffuse = 1
+        bool inputs:enableColorTemperature = 0
+        float inputs:exposure = 0
+        float inputs:intensity = 1
+        bool inputs:normalize = 0
+        float inputs:specular = 1
+        asset inputs:texture:file = @@
+        token inputs:texture:format = "automatic"
+        rel light:filters
+        rel portals
+        float primvars:arnold:camera = 0 (
+            interpolation = "constant"
+        )
+        matrix4d xformOp:transform = ( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )
+        uniform token[] xformOpOrder = ["xformOp:transform"]
+    }
+}
+
+def Xform "cameras"
+{
+    def Camera "camera1" (
+        apiSchemas = ["HoudiniCameraPlateAPI", "HoudiniViewportGuideAPI"]
+    )
+    {
+        float2 clippingRange = (1, 1000000)
+        float exposure = 0
+        float focalLength = 0.5
+        float focusDistance = 5
+        float fStop = 0
+        float horizontalAperture = 0.20955
+        float horizontalApertureOffset = 0
+        asset houdini:backgroundimage = @@
+        asset houdini:foregroundimage = @@
+        float houdini:guidescale = 1
+        uniform bool houdini:inviewermenu = 1
+        token projection = "perspective"
+        double shutter:close = 0.25
+        double shutter:open = -0.25
+        float verticalAperture = 0.11787187
+        float verticalApertureOffset = 0
+        matrix4d xformOp:transform = ( (0.9995288042127394, 0, -0.03069478048547104, 0), (-0.004382454461563712, 0.9897551376987948, -0.14270795875399597, 0), (0.030380316686031666, 0.1427752338427078, 0.9892887692474915, 0), (-1.5657610058776417, 2.6599768452283414, 15.047198989242691, 1) )
+        uniform token[] xformOpOrder = ["xformOp:transform"]
+    }
+}
+
+def Scope "Render"
+{
+    def RenderSettings "rendersettings"
+    {
+        custom int arnold:global:AA_seed
+        int arnold:global:AA_seed.timeSamples = {
+            1: 1,
+        }
+        uniform token aspectRatioConformPolicy = "expandAperture"
+        rel camera = </cameras/camera1>
+        uniform float4 dataWindowNDC = (0, 0, 1, 1)
+        uniform token[] includedPurposes = ["default"]
+        uniform bool instantaneousShutter = 0
+        uniform token[] materialBindingPurposes = ["full", "allPurpose"]
+        uniform float pixelAspectRatio = 1
+        rel products
+        uniform int2 resolution = (2048, 1152)
+    }
+}
+