What is 3D visualization?
The term 3D visualization is used synonymously with 3D graphics, 3D rendering, computer generated imagery (CGI), and other terms. They all basically refer to the process by which graphical content like images, movies etc. is created using 3D software. It’s a technology that has become mainstream over the last few decades and has evolved into one of the most viable options for producing high-quality digital content. 3D visualization is also an art that requires both artistic and technical skill. 3D artists use tools such as Autodesk 3ds Max, Maya and other software in order to generate the digital content.
When it comes to 3D product visualization, 3D artists go about the process in much the same way photographers would when setting up a shoot. They start by either modeling the product in 3D or using the existing CAD files from the engineers, and then they set up virtual cameras, virtual lights and environments and then render a frame to get the desired results.
The process has similarities to traditional photography, but the level of control and flexibility with 3D visualization is unmatched.
3D Visualization Phases
There are few phases in the 3D Visualization. Cylindo uses the following phases: 3D Modeling, Texturing, Rendering and Post Production.
3D Modelling
What is a 3D Model?
Three-dimensional (3D) models are representations of a physical body using a collection of points in 3D space, connected by various geometric entities such as triangles, lines, curved surfaces, etc.
3D models can be created by hand, by algorithms (procedural modeling), or scanned. Their surfaces may be further defined with texture mapping, but we will cover that later. Unlike a 2D image, 3D models can be viewed in specialized software suites from any angle, and can be scaled, rotated, or freely modified. The process of creating and shaping a 3D model is known as 3D modeling.
Today, 3D models are used in a wide variety of fields. The movie industry uses them as characters and objects for animated and real-life motion pictures. The video game industry uses them as assets for computer and video games. The science sector uses them as highly detailed models of chemical compounds. The architecture industry uses them to demonstrate proposed buildings and landscapes. The engineering community uses them as designs of new devices, vehicles and structures as well as a host of other uses.
Cylindo is using 3D models in its content creation and contend distribution processes.
3D Model Types
There are two primary types of 3D models that are used in the design, film & games industry, the most apparent differences being in the way they're created and manipulated (there are differences in the underlying math as well, but that's less important to the end-user).
- Polygonal Model: Polygonal models or "meshes" as they're often called, are the most common form of 3D model found in the animation, film, and games and visualization industry. Cylindo only uses Polygonal modelling for the final 3D models. Polygonal modeling – Points in 3D space, are connected by line segments to form a polygon mesh. The vast majority of 3D models today are built as textured polygonal models, because they are flexible and because computers can render them so quickly. In Cylindo we are using this approach of polygonal modeling while making the 3D models. If the client has CAD files we can use them. But if they are Curve / Surface model, than we need to convert or re-model them.
- NURBS Surface Models - A Non-uniform rational B-spline, or NURBS surface is a smooth surface model created through the use of Bezier curves (like a 3D version of the the MS Paint pen tool). To form a NURBS surface, the artist draws two or more curves in 3D space, which can be manipulated by moving handles called control vertices (CVs) along the x, y, or z axis. These models can be used mainly as a 3D reference in the visualization process.
- CAD / Solid Models - These are mainly engineering files used in the actual design and manufacture process of the products. CAD stands for Computer Aided Design. Usually these models hold information not only for the visual appearance of the items but also for the manufacture process, the inner construction, mechanisms and other elements of the item. These can generally be used as a 3D reference model for visualization purposes.
Modeling Process
3D modeling process start from a reference images or reference 3D files. Those images, which are usually front side and back are inserted in the 3D environment of the 3D Software and the modelling process begins.
The 3D artist can start from preexisting building blocks, such as primitive shapes (sphere, cube, etc.), premade elements, such as pillows, cushions etc. or even start from a single polygon and build from there. The artist constantly checks against the reference image and the dimensions to build an accurate 3D representation of the real item.
In 3D geometry, a vertex is a point where two or more curves, lines, or edges meet.
The defining characteristic of a polygonal model is that polygonal meshes are faceted, meaning the surface of the 3D model is comprised of hundreds or thousands of geometric faces. With enough smoothing, these faces become noticeable and model appears smooth and
realistic.
An edge is any point on the surface of a 3D model where two polygonal faces meet.
Manipulation of vertices on the x, y, and z-axes (affectionately referred to as "pushing and pulling verts") is the most common technique for shaping a polygonal mesh into its final shape in traditional modeling packages like Maya, 3Ds Max, etc. (Techniques are very, very different in sculpting applications like ZBrush or Mudbox.)
Polycount (Low and High Poly Models)
Again, a polygon mesh is a collection of vertices, edges and faces that defines the shape of an object in 3D computer graphics.
Traditionally the 3D artist would create a low poly version of the 3D model. At that point, depending on the use case, the artist can add more details and smooth the model, for high poly or rendering use case or the 3D artist cans tart optimizing and reducing polygons for a Low Poly 3D model for use in AR, VR or Real Time Applications such as the Cylindo Room Planner.
Example: Low poly vs high poly
UV Mapping
What is UV Mapping or UV Layout?
UV mapping or UV Layout is the process of representing the 3D surface in 2D space for texture mapping purpose. The letters "U" and "V" denote the axes of the 2D texture because "X", "Y" and "Z" are already used to denote the axes of the 3D object in model space.
UV texturing permits polygons that make up a 3D object to be painted with color (and other surface attributes) from an ordinary image. The image is called a UV texture map.
A representation of the UV mapping of a cube. The flattened cube net may then be painted to texture the cube.
UV Mapping Process
UV Mapping process is done within the 3D Modelling application or using some additional UV Mapping tools.
The UV mapping process involves flattening of the 3D shape using cutting seams in areas where those seams would naturally occur on the real item, or in areas where those seams will not be visible. The different segments or UV Shells are them moved around in a logical order.
Texturing
Texturing is the process of generating flat 2D textures that will then be used in the Rendering and applied on the 3D geometry done in modeling.
What is a Texture Map?
Texture Map is an image with specific properties that is used in the 3D application to apply fine details or emulate the real surface of the item.
Texture maps can be painted or tileable maps. Painted maps, can usually be used only on a specific item as those are specifically painted for that item. The tileable or seamless texture maps can be used on any 3D object as these maps can be repeated countless times across any object without it becoming noticeable.
Types of Texture Maps
Diffuse map
The most frequently used texture map type is the diffuse map. It can also be understood as color map. It wraps the bitmap image onto the 3D geometry surface while displaying its original pixel color.
Any bitmap image, such as scanned images or images captured by digital camera, can be used as diffuse map to represent photo realistic quality.
Example with no texture
Example with different textures
Opacity map
This map can emulate transparency and cut-out effects from grayscale images. The black part will get cut out and the white part will be fully opaque.
The gray values determine the transparency (alpha) level of the object. This can be used for meshes, nets and other complex shapes which include transparent and opaque parts.
Example with texture and an image as the mask
Example masked out
Bump map
Bump mapping uses the grayscale values of an image map to create variations in the shading of the surface to which the map is applied, to emulate surface irregularities.
It adds details to the rendered 3D models without increasing the number of polygons.
By moving around the light source we can see how the angular light projection changes the bump look. If the light is facing the surface from a straight 90 degrees angle than the bump effects are the least noticeable.
Reflection map
This texture mapping method allows parts of an object to have higher reflection and parts to have lower reflection. The same principles apply, where usually white pixels would result in higher reflection, where black pixels will result in no reflection.
With texture and an Reflection image
Reflection map only has effect within the shape
Using the same image as both Reflection and Opacity maps allows you to create special objects
Texturing Process
Here we will talk about Texturing from digital samples and from physical samples, which are the 2 processes that Cylindo is using.
Texturing from Digital Samples
If we have digital samples, the process would only include tiling of those textures to make them seamless. The process is mainly done in photoshop, where any gradients are removed, the texture is then offset so that any visible seam is removed using photoshop tools.
Before and after of a grass texture
Texturing from Physical Samples
This process besides the similar aspect of tiling as the previous method, also includes digitizing of capturing the photos from the Physical samples. That means that there has to be controlled lighting environment and accurate camera + color correction standard so that correct colors are captured.
Cylindo Lighting Setup
Rendering
What is a render?
A render is 2D representation of an object that lives in virtual 3D environment. 3D Visualization uses 3D Applications, which have virtual 3D environment, virtual 3D lights, virtual 3D Cameras, 3D Objects etc. In order for those objects to be captured in a 2D medium, such as image for use on web, movies, printing etc. those objects needs to be rendered.
During the rendering process, the computer need to process all the information that lives in the 3D application. That information is made up of many aspects such as 3D camera position, camera lens, object scale, object materials, texture maps, environments, lighting information etc. It might take several minutes up to several hours for a single image to be processed and single
rendered image to be generated.
Lighting Setup
Lighting setups in the 3D scene are virtual lights that are programmed to behave like the realistic light sources in the real world. The light falloff, light shape, light bouncing etc. are all taken into consideration.
3D Rendering Artists would use these lights are try to create realistically lit environment for the 3D object to be rendered.
Materials and Material Library
Each object needs virtual materials for it to interact with the lights and cameras and produce realistic result. These materials or shaders can have parameters for number of physical properties of the materials, such as diffuse, bumpiness, reflectivity, transparency, translucency etc. All these parameters can also use a texture map for a more realistic result.
The materials can be organized in a material library for easier manipulation.
Rendering Process
Rendering is the process of creating digital lighting setups, cameras, materials etc. that will simulate how the object would look like in reality.
The three-dimensional data that is depicted could be a complete scene including geometric models of different three dimensional objects, buildings, landscapes, and animated characters - artists need to create this scene by Modeling and Animating before the Rendering can be done.
The 3D rendering process depicts this three-dimensional scene as a picture, taken from a specified location and perspective. The rendering could add the simulation of realistic lighting, shadows, atmosphere, color, texture, and optical effects such as the refraction of light or motion-blur seen on moving objects - or the rendering might not be realistic at all, and could be designed to appear as a painting or abstract image.
Rendering sometimes takes a long time, even on very fast computers. This is because the software is essentially "photographing" each pixel of the image, and the calculation of the color of just one pixel can involve a great deal of calculation, tracing rays of light as they would bounce around the 3D scene. To render all the frames of an entire animated movie (such as Shrek, or Ice Age) can involve hundreds of computers working continuously for months or years.
This is not the case here in Cylindo since for our 360 viewer we are rendering 32 frames of the product where the product itself rotates for 360 degrees and the camera is static and this process is much faster.
For the rendering of the products we have five pre-done lighting setups and three camera heights from which the clients can choose. But this can be also modified according to the client requests.