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Field trials were conducted with two nitrogen applications (0 or 240 kg N ha−1) and three modern cultivars of winter oilseed rape (Brassica napus L.) previously selected from a root morphology screen at a young developmental stage. The purpose is to examine the relationship between root morphology and Nitrogen Uptake Efficiency (NUpE) and to test the predictiveness of some canopy optical indices for seed quality and yield. A tube-rhizotron system was used to incorporate below-ground root growth information. Practically, clear tubes of one meter in length were installed in soil at an angle of 45°. The root development was followed with a camera at key growth stages in autumn (leaf development) and spring (stem elongation and flowering). Autumn was a critical time window to observe the root development, and exploration in deeper horizons (36–48 cm) was faster without any fertilization treatment. Analysis of the rhizotron images was challenging and it was not possible to clearly discriminate between cultivars. Canopy reflectance and leaf optical indices were measured with proximal sensors. The Normalized Difference Vegetation Index (NDVI) was a positive indicator of biomass and seed yield while the Nitrogen Balance Index (NBI) was a positive indicator of above-ground biomass N concentration at flowering and seed N concentration at harvest.

Implicit surfaces have proved to be a particularly well suited and efficient model for animating and morphing shapes of arbitrary topologies. The BlobTree model is characterized as a hierarchical combination of skeletal primitives organized in a tree. The nodes hold blending, boolean and warping operators, which allows the design of complex objects. In this paper, we address the metamorphosis of the BlobTree. This appears a difficult task as the tree data‐structures of the initial and final shapes are completely different in the general case, and consequently cannot be matched easily. We propose an original technique that solves the correspondence process and creates an intermediate generic BlobTree model whose instances interpolate the initial and final shapes. The animator may control the correspondence between features and can specify both the speed of transformation and the trajectory of the nodes and the leaves of the generic BlobTree model. This provides the end user with a tight control over the transformation so as to achieve good visual effects.

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