Motivation

Ambient occlusion is a lighting technique used to give models a global illumination-like effect, as if it were lit from the entire hemisphere (rather than a point light). A set of visibility samples are collected from the hemisphere above a point, and a scalar “ambient occlusion” value is computed based on the percentage of unoccluded samples. For a nice overview of ambient occlusion, check out Steve Hill’s article in Gamastura. Some other very good ambient occlusion tutorials have been written by Zhang Jian, Bob Moyer, and Andrew Whitehurst.

Approaches

There are two basic approaches for computing ambient occlusion. The first is ray tracing; simply shoot out rays in uniform pattern across the hemisphere. The percentage of rays that hit geometry is divided by the total number of rays to get a scalar value. This could also be done with hardware rendering by placing a camera at every triangle and counting the percentage of the hemisphere that is visible. Since this requires computing occlusion at every triangle, this approach is in general O(N^2), although with efficiency structures (such as bounding volume hierarchies) it can be reduced to O(NlogN).

The second approach is an “outside-looking-in” approach. The model is rendered from a set of M random points on the sphere surrounding the model. The occlusion information is stored for each viewpoint, and averaged. The complexity of this approach is O(N*M), or O(MlogN) with efficiency structures. Since M is generally much smaller than N, this makes it interesting for realtime work. Since this is the approach I am interested in, let me explain the algorithm in more detail.

goto full Assorted Notes :

http://www.cs.unc.edu/~coombe/research/ao/

3d Modeling Services Gives a Better Look to Website

Author: Mike Roy

3D or three Dimension which precisely means giving a 3D effect to any image. 3D Modeling services improves your graphics & gives a better look to your website. 3d Art can be used for 3D Character animation, 3D modeling, 3D graphic, 3D background, and 3D logo. Now a day 3D is widely being used along with Computer Design. 3D can be used in Architectural, Mechanical or Structural related projects.

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3d Modeling

Author: Flatpyramid

3D Modeling is the creation, manipulation, and storage of geometric objects to represent objects that are all around us or virtual objects. The process of 3d modeling begins with the use of specialized 3d modeling software. The 3D artist develops a mathematical, wireframe representation of the object using specialized software. The final product is called a 3D model.

The 3d modeling process for 3D computer graphics is similar to sculpting. During this process geometric data is manipulated and prepared manually or automatically. There are three methods for creating and representing a 3d model. They are: polygonal 3d modeling, NURBS 3d modeling, and Splines and Patched 3d modeling.
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From Wikipedia

Adobe Photoshop, or simply Photoshop, is a graphics editing program developed and published by Adobe Systems. It is the current and primary market leader  for commercial bitmap and image manipulation, and is theflagship product of Adobe Systems. It has been described as “an industry standard for graphics professionals”  and was one of the early “killer applications” on the PC.

Adobe’s 2005 “Creative Suite” rebranding led to Adobe Photoshop 8′s renaming to Adobe Photoshop CS. Thus, Adobe Photoshop CS4 is the 11th major release of Adobe Photoshop. The CS rebranding also resulted in Adobe offering numerous software packages containing multiple Adobe programs for a reduced price. Adobe Photoshop is included in most of Adobe’s Creative Suite offerings.

Due to its popularity, “photoshop” has become both a verb to refer to photo editing and a genericized trademark for graphics editing software. Photoshop’s popularity, combined with its high retail price, makes Photoshop’s piracy raterelatively high.  Adobe countered by including SafeCast DRM starting with Adobe Photoshop CS.
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Adobe Photoshop Elements is the consumer version of the Adobe Photoshop raster image editing product, sold at a fraction (roughly 1/6th) of the cost of the professional product. It contains most of the features of the professional version but with fewer and simpler options. The program allows users to create, edit, organize and share images, all from the same product.

Originally introduced alongside Photoshop version 7, Photoshop Elements targets photography enthusiasts and thus lacks many features that make it useful in a proper print production environment. For example, Photoshop Elements cannot export files in the CMYK color mode, supports a simplified color management system, and excludes detailed soft-proofing. It also either eliminates completely or offers simplified versions of some of the more powerful plug-ins, along with a number of features aimed at non-experts (such as removing the red-eye effect or changing the skin tone in a picture). An example of a redesigned feature would be the Variations correction dialog. Some versions can, however, open, edit, and savePDFs.

Photoshop LE (Limited Edition) was Adobe’s consumer raster image editing product prior to the introduction of Elements. Photoshop LE had similar limitations to Elements.

Start downloading Adobe Photoshop Elements 6.0 for Macintosh in minutes  at Adobe.com.

Animating a 3d Model

Author: Flatpyramid

Unlike movies that consist of many frames, 3D models cannot be animated by using the typical amount of frames per second which our eye attributes as blurring and creates on stable image – such as frames per second becoming the movies that we are used to seeing on a daily basis. Creating a 3D model that is to be used for animation is significantly different than creating a 3D model that will not be animated.

Creating a model for animation means that less attention will be paid to the background of the 3D model. Focus is going to be on what is moving within the scene, and this is the 3D model.

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The Creation Process of a 3d Model: Rendering

Author: Flatpyramid

Rendering is the third and final step in the simple creation of a 3D model. Rendering refers to the image being visualized with images being created from the 3D model.

There are many features of a rendering, these include; transparency, shading, shadows, reflection, depth of field, caustics, fogging, bump-mapping and texture mapping. These features are the most commonly used when an object has been rendered.

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3d Modeling Can Improve the Design Process

Author: cad outsourcing

3D modeling has capabilities to allow us to create 3D images that are as realistic as the actual objects. These images are called 3D models. These models are just like a physical model, but these can be rotated on the screen. We can display isometrics or perspectives views from a 3D model, from any angle with a few simple steps.

3D modeling is the process of developing a mathematical, wireframe representation of any three-dimensional object (either inanimate or living) via specialized software. 3D Model can be displayed as a two-dimensional (2D) image through a process called 3D rendering or used in a computer simulation. The model can also be physically created using 3D Printing devices.

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3d Models and Their Uses

Author: Flatpyramid

3D or three dimensional models are used for a variety of purposes. Surgeons and filmmakers are only two of the many professions that use 3D models on a regular basis. 3D models are created by mapping various coordinates in a 3D space.

Medical professionals use detailed 3D models of organs to teach medical students, outline and plan surgical intervention as well as demonstrate procedures to students and patients. Plastic surgeons use detailed software to create 3D models of the body to demonstrate a “before and after” to the potential patient.

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3d Printers for 3d Models

Author: 3D John

3D printers are today creating a revolution in the rapid prototyping industry. Rapid prototyping technology (RPT) utilizes computer assisted design software incorporated into 3D printers which allow companies to create 3D Models during all phases of the product development process. The prototypes created by the 3D printers can then be used by marketing agencies to incorporate further enhancements and improvements into the designs. 3D printers used for rapid prototyping technology are able to produce models quicker, easier and more cost efficient then traditional model making techniques. The tremendous application potential for 3D printers and rapid prototyping technology is just beginning to be realized and will continue to play an important role in designing and creating 3D models for decades to come.

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