Abstract: Computational cost is one of the major problems in animating smoke. Recently, adaptive grid refinement using octree structure has been proposed, which is a successful method for reducing the computational cost of a detail-preserving fluid simulation. Although octree grid is optimized for details, viewing is not addressed. Smoke distant from the viewing screen which usually has less visual attention and is unnecessary for high-detail simulation can be optimized for speed. However, applying such view-dependent optimization to the octree grid directly may cause animation artifacts and loss in natural fluid behaviours. This paper, we present a method for view-dependent adaptive grid refinement, extending the traditional octree grid by considering the viewing frustum, as well as variation in fluid quantities as criteria for grid refinement. In our method, refinement conditions with adaptive thresholds are proposed to optimize the grid for both view and details. Additionally, our method preserves visual details and fluid behaviours which allows high-detail smoke animations in relatively less amount of computational cost consumption, especially when applied for large scale simulations.