3D Tree Models Research Articles

Fast Photo‐Realistic Rendering of Trees in Daylight

Abstract We propose a fast approach for photo‐realistic rendering of trees under various kinds of daylight, which is particularlyuseful for the environmental assessment of landscapes. In our approach the 3D tree models are transformedto a quasi‐3D tree database registering geometrical and shading information of tree surfaces, i.e. their normalvectors, relative depth, and shadowing of direct sunlight and skylight, by using a combination of 2D buffers.Thus the rendering speed of quasi‐3D trees depends on their display sizes only, regardless of the complexity oftheir original 3D tree models. By utilizing a two‐step shadowing algorithm, our proposed method can create highquality forest scenes illuminated by both sunlight and skylight at a low cost. It can generate both umbrae andpenumbrae on a tree cast by other trees and any other objects such as buildings or clouds. Transparency, specularreflection and inter‐reflection of leaves, which influence the delicate shading effects of trees, can also be simulatedwith verisimilitude. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three dimensional Graphics and Realism

Toward a better understanding of texture in vascular CT scan simulated images.

This paper shows the influence of computed tomography slice thickness on textural parameters by simulating realistic images issued from: 1) a 3D model of vascular tree, with structural and functional features and in which angiogenesis is related to the organ growth; 2) a projection/reconstruction process using fast Fourier transform. Texture analysis is performed by means of second-order statistics and gradient based methods.

Reconstructing 3D tree models from instrumented photographs

Our computer modeling technique reproduces a tree's 3D volume and skeleton from instrumented photographs. The technique involves first constructing the skeleton (trunk and the major branches) of the tree, and then applying an L-system starting from this skeleton. L-systems are one of the better known procedural models in the graphics community, especially after their popularization by P. Prusinkiewicz and A. Lindenmayer (1990).