Browse Definitions :
Definition

3D modeling

3-D modeling is the use of software to create a virtual three-dimensional model of some physical object.

3-D modeling is used in many different industries, including virtual reality, video games, 3D printing, marketing, TV and motion pictures, scientific and medical imaging and computer-aided design and manufacturing CAD/CAM.

3-D modeling software generates a model through a variety of tools and approaches including:

  • simple polygons.
  • 3-D primitives -- simple polygon-based shapes, such as pyramids, cubes, spheres, cylinders and cones.
  • spline curves.
  • NURBS (non-uniform rational b-spline) -- smooth shapes defined by bezel curves, which are relatively computationally complex.

2-D geometric polygon shapes are used extensively in motion picture effects and 3-D video game art. Creating approximations of shapes made with polygons is much more efficient in raster graphics, which are required for real time 3-D gaming.

In art for video games and motion picture effects, a model might start as a rough-out using polygon primitives or NURBS, or as a design made by following contours on multiple 2-D isometric views. If the model is to be animated, careful consideration of the arrangement of continuous edge loops must be maintained in the model’s polygons around areas of deformation such as joints. A model that looks good stationary will fold faster than Superman's laundry in animation when the appearance of the stationary end model is all that’s considered during building.

Once a model is adequately built, an artist might arrange the coordinates of the model to match its 2-D textures in a process called UV mapping, a process that is kind of like trying to design and tailor with a computer mouse. Areas that require more detail are given more space in the UV map. This can be done either using a repeating texture such as a checker board as a place holder or by using an existing texture.

Generally the next step might be to texture the model, which is to apply either hand-painted or photograph-based 2-D images, usually TGA (Targa bitmap), to the model that will define:

  • Its color with a color map.
  • Its reflectivity and reflected color with a specular map.
  • Its surface texture, defined through light-play with a bump or normal map, or a deformation map for actual added geometric detail.

Animated models require an extra step of rigging, which is like giving them a virtual skeleton with bones and joints along with the controllers to manage it. The way the texture of these joints influences the surface texture under deformation must be defined in skinning, where one paints the weight of joint influence on the textures directly on the models polygons; a polygon painted more heavily is more heavily influenced by a selected joint’s movement. The model is then ready for the animator.

More computational and expensive methods of making models such as NURBS may be used, along with complex shaders that interact with particle-based light, in rendered graphics when real time is not a necessity.

This was last updated in April 2016

Continue Reading About 3D modeling

SearchCompliance
  • OPSEC (operations security)

    OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines ...

  • smart contract

    A smart contract is a decentralized application that executes business logic in response to events.

  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

SearchSecurity
  • cyberterrorism

    According to the U.S. Federal Bureau of Investigation, cyberterrorism is any 'premeditated, politically motivated attack against ...

  • biometrics

    Biometrics is the measurement and statistical analysis of people's unique physical and behavioral characteristics.

  • privileged access management (PAM)

    Privileged access management (PAM) is the combination of tools and technology used to secure, control and monitor access to an ...

SearchHealthIT
SearchDisasterRecovery
  • What is risk mitigation?

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • change control

    Change control is a systematic approach to managing all changes made to a product or system.

  • disaster recovery (DR)

    Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

SearchStorage
  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

  • VRAM (video RAM)

    VRAM (video RAM) refers to any type of random access memory (RAM) specifically used to store image data for a computer display.

  • virtual memory

    Virtual memory is a memory management technique where secondary memory can be used as if it were a part of the main memory.

Close