The Research Of Non-Photorealistic Rendering On Simulating Painting

In recent years, the development of Non-Photorealistic rendering technology which simulates some art style is getting people's attention and becoming a hot spot of Non-Photorealistic Graphics. However, as a new research field, especially because of the uncertainty of judgment, Non-Photorealistic is still developing in many aspects. To obtain the basic light and shade hue of scene in non-photorealistic rendering with computer must be solved, although we could store the light and shade hue as"knowledge"into computer, but, constructing an enough sufficient repository and the corresponding illation mechanism is also difficult. In fact, in the course of painting charcoal drawing, the setup of hue is not need to accurately obtain every pixel's light and shade hue like shooting photos, only grasping the overall light and shade hue of the scene and objects between objects in it is enough.Hereby, this paper researches on the method of Non-Photorealistic rendering, and puts forward a Non-Photorealistic rendering method of charcoal drawing painting based on hue extraction and brushwork mode. Innovated works incarnate in such aspects: (1) Obtaining the shelter information which one object is sheltered by other objects in scene, by the way of method of obtaining objects shelter information based on facet"extractor"; (2) Establishing the brushwork mode which simulating canvas and pencil charcoal drawing, here the brushwork mode which simulates canvas includes facet brushwork, spherule brushwork and so on; Classifying pencil line brushwork mode into upright-line brushwork, transverse-line brushwork and arc-line brushwork these three kinds based on pencil charcoal drawing's characteristic; (3) Considering the pencil charcoal drawing's characteristic, we establish the brushwork painting mode based on brushwork painting swatch in the carving up area and beforehand saving area, it could greatly enhance the painting speed; (4) Based on the former work, we give the course of the simulating canvas the pencil charcoal drawing painting.This method explores a new approach for non-photorealistic pencil charcoal drawing; it creates non-photorealistic canvas and charcoal drawing pencil painting which have light and shade effect in 3D scene based on the established rendering mode. This method computes simply, the process towards the object information of painted charcoal drawing is identical and easy to locally amend at the same time. The experiment results testify the validity of this method.