4 research outputs found
Enabling Viewpoint Learning through Dynamic Label Generation
Optimal viewpoint prediction is an essential task in many computer graphics
applications. Unfortunately, common viewpoint qualities suffer from two major
drawbacks: dependency on clean surface meshes, which are not always available,
and the lack of closed-form expressions, which requires a costly search
involving rendering. To overcome these limitations we propose to separate
viewpoint selection from rendering through an end-to-end learning approach,
whereby we reduce the influence of the mesh quality by predicting viewpoints
from unstructured point clouds instead of polygonal meshes. While this makes
our approach insensitive to the mesh discretization during evaluation, it only
becomes possible when resolving label ambiguities that arise in this context.
Therefore, we additionally propose to incorporate the label generation into the
training procedure, making the label decision adaptive to the current network
predictions. We show how our proposed approach allows for learning viewpoint
predictions for models from different object categories and for different
viewpoint qualities. Additionally, we show that prediction times are reduced
from several minutes to a fraction of a second, as compared to state-of-the-art
(SOTA) viewpoint quality evaluation. We will further release the code and
training data, which will to our knowledge be the biggest viewpoint quality
dataset available
Category‐Specific Salient View Selection via Deep Convolutional Neural Networks
In this paper, we present a new framework to determine up front orientations and detect salient views of 3D models. The salient viewpoint to human preferences is the most informative projection with correct upright orientation. Our method utilizes two Convolutional Neural Network (CNN) architectures to encode category-specific information learnt from a large number of 3D shapes and 2D images on the web. Using the first CNN model with 3D voxel data, we generate a CNN shape feature to decide natural upright orientation of 3D objects. Once a 3D model is upright-aligned, the front projection and salient views are scored by category recognition using the second CNN model. The second CNN is trained over popular photo collections from internet users. In order to model comfortable viewing angles of 3D models, a category-dependent prior is also learnt from the users. Our approach effectively combines category-specific scores and classical evaluations to produce a data-driven viewpoint saliency map. The best viewpoints from the method are quantitatively and qualitatively validated with more than 100 objects from 20 categories. Our thumbnail images of 3D models are the most favoured among those from different approaches.11Nsciescopu