NVIDIA NCP-OUSD Exam - Topic 2 Question 2 Discussion

An authored opinion may be valid and still not appear in the final composed stage because USD resolves competing opinions by strength ordering. NVIDIA's Learn OpenUSD strength-ordering guide explains that, for each prim and property, the composition engine evaluates opinions from contributing layers and composition arcs using LIVRPS, giving precedence to stronger opinions when conflicts occur. It also states that stronger layers can override or add to data defined in weaker layers, enabling non-destructive edits and overrides.

Option D is correct because a weaker layer's opinion can be hidden by a stronger opinion authored elsewhere in the layer stack or through a stronger composition context. This is a normal result of USD composition, not an error. Option A is incorrect because editability controls whether a layer can be modified, not whether its authored opinions can contribute during composition. Option B may indicate invalid or poorly modeled data, but schema choice alone is not the general reason an opinion loses. Option C can be a troubleshooting case for missing referenced content, but the question asks why opinions from a composed layer may not take effect. This aligns with Composition Layer Stacks, Opinion Strength, LIVRPS, Value Resolution, and Non-Destructive Overrides.