fixes lookAt calculation for loading toWorld property in mitsuba scene

Author: keptsecret

src/nbl/ext/MitsubaLoader/PropertyElement.cpp

@@ -258,10 +258,14 @@ std::optional<SNamedPropertyElement> CPropertyElementManager::createPropertyData
 					up[index] = 1.f;
 				}
 				// TODO: after the rm-core matrix PR we need to get rid of the tranpose (I transpose only because of GLM and HLSL mixup)
-				const auto lookAtGLM = reinterpret_cast<const hlsl::float32_t4x4&>(glm::lookAtLH<float>(origin,target,up));
-				const auto lookAt = hlsl::transpose(lookAtGLM);
+				//const auto lookAtGLM = reinterpret_cast<const hlsl::float32_t4x4&>(glm::lookAtLH<float>(origin,target,up));
+				//const auto lookAt = hlsl::transpose(lookAtGLM);
+				const auto lookAt = hlsl::math::linalg::rhLookAt(origin, target, up);
 				// mitsuba understands look-at and right-handed camera little bit differently than I do
 				const auto rotation = hlsl::inverse(hlsl::float32_t3x3(lookAt));
+				for (auto i = 0; i < 3; i++)
+					for (auto j = 0; j < 3; j++)
+						result.mvalue[i][j] = rotation[i][j];
 				// set the origin to avoid numerical issues
 				for (auto r=0; r<3; r++)
 				{