From d657e628f0fc224874d83f4bbaf40b3dfe1e6b0e Mon Sep 17 00:00:00 2001
From: Robin Alazard <robinalazard@google.com>
Date: Tue, 29 Apr 2025 08:43:23 -0700
Subject: [PATCH] Fix radius sizes of geom shapes

PiperOrigin-RevId: 752750452
Change-Id: I2ac08ad4014718320f014ed8ba7cc3b87586f6c0
---
 .../usd/plugins/mjcf/mujoco_to_usd.cc          | 18 ++++++++----------
 .../usd/plugins/mjcf/mjcf_file_format_test.cc  |  8 ++++----
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/src/experimental/usd/plugins/mjcf/mujoco_to_usd.cc b/src/experimental/usd/plugins/mjcf/mujoco_to_usd.cc
index e443149c..8ddba52d 100644
--- a/src/experimental/usd/plugins/mjcf/mujoco_to_usd.cc
+++ b/src/experimental/usd/plugins/mjcf/mujoco_to_usd.cc
@@ -673,15 +673,15 @@ class ModelWriter {
     pxr::SdfPath capsule_path =
         CreatePrimSpec(data_, body_path, name, pxr::UsdGeomTokens->Capsule);
 
-    // MuJoCo uses half sizes.
     pxr::SdfPath radius_attr_path =
         CreateAttributeSpec(data_, capsule_path, pxr::UsdGeomTokens->radius,
                             pxr::SdfValueTypeNames->Float);
-    SetAttributeDefault(data_, radius_attr_path, size[0] * 2);
+    SetAttributeDefault(data_, radius_attr_path, size[0]);
 
     pxr::SdfPath height_attr_path =
         CreateAttributeSpec(data_, capsule_path, pxr::UsdGeomTokens->height,
                             pxr::SdfValueTypeNames->Float);
+    // MuJoCo uses half sizes.
     SetAttributeDefault(data_, height_attr_path, size[1] * 2);
     return capsule_path;
   }
@@ -701,15 +701,15 @@ class ModelWriter {
     pxr::SdfPath cylinder_path =
         CreatePrimSpec(data_, body_path, name, pxr::UsdGeomTokens->Cylinder);
 
-    // MuJoCo uses half sizes.
     pxr::SdfPath radius_attr_path =
         CreateAttributeSpec(data_, cylinder_path, pxr::UsdGeomTokens->radius,
                             pxr::SdfValueTypeNames->Float);
-    SetAttributeDefault(data_, radius_attr_path, size[0] * 2);
+    SetAttributeDefault(data_, radius_attr_path, size[0]);
 
     pxr::SdfPath height_attr_path =
         CreateAttributeSpec(data_, cylinder_path, pxr::UsdGeomTokens->height,
                             pxr::SdfValueTypeNames->Float);
+    // MuJoCo uses half sizes.
     SetAttributeDefault(data_, height_attr_path, size[1] * 2);
     return cylinder_path;
   }
@@ -729,11 +729,10 @@ class ModelWriter {
     pxr::SdfPath ellipsoid_path =
         CreatePrimSpec(data_, body_path, name, pxr::UsdGeomTokens->Sphere);
 
-    pxr::GfVec3f scale = {static_cast<float>(size[0] * 2),
-                          static_cast<float>(size[1] * 2),
-                          static_cast<float>(size[2] * 2)};
+    pxr::GfVec3f scale = {static_cast<float>(size[0]),
+                          static_cast<float>(size[1]),
+                          static_cast<float>(size[2])};
 
-    // MuJoCo uses half sizes.
     pxr::SdfPath radius_attr_path =
         CreateAttributeSpec(data_, ellipsoid_path, pxr::UsdGeomTokens->radius,
                             pxr::SdfValueTypeNames->Float);
@@ -760,11 +759,10 @@ class ModelWriter {
     pxr::SdfPath sphere_path =
         CreatePrimSpec(data_, body_path, name, pxr::UsdGeomTokens->Sphere);
 
-    // MuJoCo uses half sizes.
     pxr::SdfPath radius_attr_path =
         CreateAttributeSpec(data_, sphere_path, pxr::UsdGeomTokens->radius,
                             pxr::SdfValueTypeNames->Float);
-    SetAttributeDefault(data_, radius_attr_path, size[0] * 2);
+    SetAttributeDefault(data_, radius_attr_path, size[0]);
     return sphere_path;
   }
 
diff --git a/test/experimental/usd/plugins/mjcf/mjcf_file_format_test.cc b/test/experimental/usd/plugins/mjcf/mjcf_file_format_test.cc
index f144da6e..78f10f46 100644
--- a/test/experimental/usd/plugins/mjcf/mjcf_file_format_test.cc
+++ b/test/experimental/usd/plugins/mjcf/mjcf_file_format_test.cc
@@ -472,16 +472,16 @@ TEST_F(MjcfSdfFileFormatPluginTest, TestGeomsPrims) {
   // Sphere
   EXPECT_PRIM_VALID(stage, "/test/sphere_geom");
   EXPECT_PRIM_IS_A(stage, "/test/sphere_geom", pxr::UsdGeomSphere);
-  ExpectAttributeEqual(stage, "/test/sphere_geom.radius", 2 * 10.0);
+  ExpectAttributeEqual(stage, "/test/sphere_geom.radius", 10.0);
   // Capsule
   EXPECT_PRIM_VALID(stage, "/test/capsule_geom");
   EXPECT_PRIM_IS_A(stage, "/test/capsule_geom", pxr::UsdGeomCapsule);
-  ExpectAttributeEqual(stage, "/test/capsule_geom.radius", 2 * 10.0);
+  ExpectAttributeEqual(stage, "/test/capsule_geom.radius", 10.0);
   ExpectAttributeEqual(stage, "/test/capsule_geom.height", 2 * 20.0);
   // Cylinder
   EXPECT_PRIM_VALID(stage, "/test/cylinder_geom");
   EXPECT_PRIM_IS_A(stage, "/test/cylinder_geom", pxr::UsdGeomCylinder);
-  ExpectAttributeEqual(stage, "/test/cylinder_geom.radius", 2 * 10.0);
+  ExpectAttributeEqual(stage, "/test/cylinder_geom.radius", 10.0);
   ExpectAttributeEqual(stage, "/test/cylinder_geom.height", 2 * 20.0);
   // Ellipsoid
   EXPECT_PRIM_VALID(stage, "/test/ellipsoid_geom");
@@ -490,7 +490,7 @@ TEST_F(MjcfSdfFileFormatPluginTest, TestGeomsPrims) {
   EXPECT_PRIM_IS_A(stage, "/test/ellipsoid_geom", pxr::UsdGeomSphere);
   ExpectAttributeEqual(stage, "/test/ellipsoid_geom.radius", 1.0);
   ExpectAttributeEqual(stage, "/test/ellipsoid_geom.xformOp:scale",
-                       pxr::GfVec3f(2.0 * 10.0, 2.0 * 20.0, 2.0 * 30.0));
+                       pxr::GfVec3f(10.0, 20.0, 30.0));
 }
 
 static constexpr char kSiteXml[] = R"(