The paper presents a new data structure called a shadow pyramid for storing 3D objects to reduce the shadow-testing time during ray tracing. For each primitive object that first intersects a ray, a shadow pyramid is constructed in which all the candidate objects that possibly block the path from the relevant light source to any point on the primitive object are registered. Shadow testing of. th...

In this paper we describe a real-time shadow generation with volume shadow algorithm in virtual environment that is illuminated by light sources with possibility to move separately. This algorithm uses the combination of stencil and Z-buffers to generate shadow volume. It is simple to understand and implement. We have significantly improved and implemented recent techniques that are used in sha...

cercis siliquastrum is compatible to soil types and has resistance to climate changes. therefore the study of its germination and growth condition can lead us to correct use for semi-arid lands in iran. in this research the effect of different treatment on cercis siliquastrum germination and growth indices was investigated and the most effective treatment was distinguished. thus, five frequenci...

A method of generating Deep Shadow Maps from a 3D data set is presented. This method uses ray tracing on the GPU to accumulate opacity and store them in a deep shadow map. The deep shadow map is then sampled based on view direction to determine how much light got to a particular fragment. The shadow maps can also be used to cast shadows onto other objects.

We used a visual-search method to investigate the role of shadows in the rapid discrimination of scene properties. Targets and distractors were light or dark 2-D crescents of identical shape and size, on a mid-grey background. From the dark stimuli, illusory 3-D shapes can be created by blurring one arc of the crescent. If the inner arc is blurred, the stimulus is perceived as a curved surface ...

Shadows are important to computer graphics because they add realism and help the viewer identify spatial relationships. Shadows are also useful story-telling devices. For instance, artists carefully choose the shape, softness, and placement of shadows to establish mood or character. Many shadow generation techniques developed over the years have been used successfully in offline movie productio...

The GLT project is deploying a new submillimeter (submm) VLBI station in Greenland. Our primary scientific goal is to image a shadow of the supermassive black hole (SMBH) of six billion solar masses in M87 at the center of the Virgo cluster of galaxies. The expected SMBH shadow size of 40-50 μas requires superbly high angular resolution, suggesting that the submm VLBI would be the only way to o...

Various visual functions decline in ageing and even more so in patients with Alzheimer's disease (AD). Here we investigated whether the complex visual processes involved in ignoring illumination-related variability (specifically, cast shadows) in visual scenes may also be compromised. Participants searched for a discrepant target among items which appeared as posts with shadows cast by light-fr...