Merge pull request #152 from blaztinn/additive_rotation_fix

Additive rotation fix
guillaumeblanc · Feb 17, 2024 · dd2c662 · dd2c662
2 parents 0213522 + ef6654f
commit dd2c662
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Showing 3 changed files with 56 additions and 3 deletions.
diff --git a/src/animation/offline/additive_animation_builder.cc b/src/animation/offline/additive_animation_builder.cc
@@ -63,7 +63,7 @@ math::Float3 MakeDeltaTranslation(const math::Float3& _reference,
 
 math::Quaternion MakeDeltaRotation(const math::Quaternion& _reference,
                                    const math::Quaternion& _value) {
-  return _value * Conjugate(_reference);
+  return Conjugate(_reference) * _value;
 }
 
 math::Float3 MakeDeltaScale(const math::Float3& _reference,

diff --git a/src/animation/runtime/blending_job.cc b/src/animation/runtime/blending_job.cc
@@ -129,7 +129,7 @@ namespace {
     const math::SoaQuaternion interp_quat = {                                \
         rotation.x * _simd_weight, rotation.y * _simd_weight,                \
         rotation.z * _simd_weight, (rotation.w - one) * _simd_weight + one}; \
-    _out.rotation = NormalizeEst(interp_quat) * _out.rotation;               \
+    _out.rotation = _out.rotation * NormalizeEst(interp_quat);               \
     _out.scale =                                                             \
         _out.scale * (one_minus_weight_f3 + (_in.scale * _simd_weight));     \
   } while (void(0), 0)
@@ -147,7 +147,7 @@ namespace {
     const math::SoaQuaternion interp_quat = {                                  \
         rotation.x * _simd_weight, rotation.y * _simd_weight,                  \
         rotation.z * _simd_weight, (rotation.w - one) * _simd_weight + one};   \
-    _out.rotation = Conjugate(NormalizeEst(interp_quat)) * _out.rotation;      \
+    _out.rotation = _out.rotation * Conjugate(NormalizeEst(interp_quat));      \
     const math::SoaFloat3 rcp_scale = {                                        \
         math::RcpEst(math::MAdd(_in.scale.x, _simd_weight, one_minus_weight)), \
         math::RcpEst(math::MAdd(_in.scale.y, _simd_weight, one_minus_weight)), \

diff --git a/test/animation/runtime/blending_job_tests.cc b/test/animation/runtime/blending_job_tests.cc
@@ -781,6 +781,59 @@ TEST(AdditiveWeight, BlendingJob) {
   }
 }
 
+TEST(AdditiveRotationFromNonIdentity, BlendingJob) {
+  using ozz::math::GetW;
+  using ozz::math::GetX;
+  using ozz::math::GetY;
+  using ozz::math::GetZ;
+
+  const ozz::math::SoaTransform identity = ozz::math::SoaTransform::identity();
+
+  // Initialize rest pose.
+  ozz::math::SoaTransform rest_poses[1] = {identity};
+  rest_poses[0].rotation = ozz::math::SoaQuaternion::Load(
+      ozz::math::simd_float4::Load(0.f, .70710677f, .382683432f, 0.f),
+      ozz::math::simd_float4::Load(0.f, 0.f, 0.f, .70710677f),
+      ozz::math::simd_float4::Load(0.f, 0.f, 0.f, 0.f),
+      ozz::math::simd_float4::Load(1.f, .70710677f, .9238795f, -.70710677f));
+
+  // Initialize inputs.
+  ozz::math::SoaQuaternion input_half_rotation = ozz::math::SoaQuaternion::Load(
+      ozz::math::simd_float4::Load(.70710677f, 0.f, 0.f, .382683432f),
+      ozz::math::simd_float4::Load(0.f, 0.f, .70710677f, 0.f),
+      ozz::math::simd_float4::Load(0.f, 0.f, 0.f, 0.f),
+      ozz::math::simd_float4::Load(.70710677f, 1.f, -.70710677f, .9238795f));
+  ozz::math::SoaTransform input_transforms[1] = {identity};
+  input_transforms[0].rotation = input_half_rotation * input_half_rotation;
+
+  ozz::math::SoaQuaternion expected_rotation =
+      rest_poses[0].rotation *
+      Conjugate(input_half_rotation * input_half_rotation);
+  constexpr float weights[]{-1.0f, -0.5f, 0.0f, 0.5f, 1.0f};
+  for (float weight : weights) {
+    BlendingJob::Layer layers[1];
+    layers[0].transform = input_transforms;
+
+    ozz::math::SoaTransform output_transforms[1];
+
+    BlendingJob job;
+    job.additive_layers = layers;
+    job.rest_pose = rest_poses;
+    job.output = output_transforms;
+
+    layers[0].weight = weight;
+    EXPECT_TRUE(job.Run());
+
+    ozz::math::SimdFloat4 dot =
+        ozz::math::Dot(expected_rotation, output_transforms[0].rotation);
+    ozz::math::SimdFloat4 distance =
+        ozz::math::simd_float4::one() - (dot * dot);
+    EXPECT_SIMDFLOAT_EQ_EST(distance, 0.0f, 0.0f, 0.0f, 0.0f);
+
+    expected_rotation = expected_rotation * input_half_rotation;
+  }
+}
+
 TEST(AdditiveJointWeight, BlendingJob) {
   const ozz::math::SoaTransform identity = ozz::math::SoaTransform::identity();