Terms & Concepts Architecture 160 Intro to 3d Modeling
Lecture Topics• The Cartesian Coordinate System• Types of 3d Modeling Suites• Orientation of "Normals"• Breakdown of Model Parts• Comparison of 3d File Types• Imaging Terminology• Comparison of Image File Types• Rendering - In Brief• For next Class...
Cartesian Coordinate System• This is the coordinate system that SketchUp, and in fact most modeling suites are based around.• The axes used in SketchUp are as follows: o X (Red) o Y (Green) o Z (Blue)
Types of Modelers• Polygon Mesh Modeling o Models consist of surfaces that are comprised of polygonal faces. Vertices define the endpoints of line segments, and segments define the edges of polygons. o SketchUp, 3DS Max, and Cinema 4D are all examples of polygon mesh modeling suites, although SketchUps methods are somewhat hybridized.
Types of Modelers• NURBS - Non-uniform Rational B-Splines o Models consist of surfaces that are comprised of mathematically calculated curves. o Rhino & Autodesk Maya are two suites that use NURBS heavily, and very well. Example:B-splines are defined by the mathematical average of o SketchUp does NOT support true control points (green), whose NURBS, but plugins are continually "weight" pulls the spline into position (blue). adding new features that are similar.
Normal Orientations• An important concept to understand about 3d modeling is the idea of "surface normals".• Surface normals are represented as a vector pointing perpendicularly outward from a surface, as represented by the diagram to the right.• Proper orientation of surface normals allow for models to correctly display textures and material properties, and are therefore critical for good modeling technique. A surface normal, whose• Well cover orientation in SketchUp once we orientation is represented by the blue arrow. start modeling, but being aware of it is critical from the beginning.
Polygon Meshes•• Vertex - Individual points that define the endpoints of edges.• Edges - Individual lines that define the boundaries of faces.• Faces - Individual flat faces make up larger polygons/surfaces. Polygons - Polygons are made up of multiple flat faces, and are treated as• one. Surfaces - Larger groups of polygons are treated as one single surface.
3d File Terminology• .skp - Native SketchUp File Type o This is the file type well be encountering the most. Its the default type that utilized by SketchUp, and is capable of being imported/used in other software types. o This format not only stores geometry and textures, but often contains other file definitions (trees, cars, etc.), so that it does not require any additional files if moved. Consequently, these files can get very large if careful techniques are not observed, but can be very helpful if they are.• .dwg/.dxf - Autodesk Drawing/Exchange Format o Autodesks .dwg/.dxf are currently the most popular format for bringing in architectural and product design objects in SketchUp. These often, however, require significant cleanup for proper use, and should only be used as reference.
3d File Terminology• .obj - Wavefront 3d object file o Now the most widely accepted archival file type, these models are contain information about both a models geometry and texture setups, and therefore are normally easy to set up and work with as long as they have been set up to certain specifications. o This file type is more popular because it is a text/plain file type. This means that more of the geometry is readable by the computer, and therefore is easier to work with. If you were to open this file, it includes text and english characters.• .3ds - 3D Studio Max o This file type was the original file type of the 3d modeling software of the same name. o The .3ds file type is less popular because it is a binary file, meaning it consists of 0s and 1s. This limits the amount of geometry the file can contain to 65,536 vertices. As you can imagine, this limitation puts a rather significant handicap on the file type.
Image Terminology• Raster Graphics o These types of images (often referred to a bitmaps in general) are based on pixels, and are not infinitely scalable. They are created by digital cameras, and by softwares like Adobe Photoshop and GIMP.• Vector Graphics o These types of images are used in web graphics, and are infinitely scalable without loss of quality. They are created with softwares as Adobe Illustrator and Inkscape.
Image File Types• .jpg - Joint Photographic Experts Group o Now an actual file type, this was originally the name of the compression applied to pictures. This image type is normally referred to as a "lossy" format, which means that once this compression is applied, quality is lost, and the action cannot be reversed. o These are the most common image types well be dealing with, but due to their lossy nature, Ill be teaching you how to work with them so as not to lose detail, but maintain a reasonable file size.• .png - Portable Network Graphic o This file type can grant several significant bonuses over .jpg if used properly, including "lossless" compression. o These image types also support a feature called alpha channel transparency, which allows an image to have a transparent background, removing the need to cut out backgrounds in photoshop, or mask out areas of photographs or textures. Well cover alpha channels in more depth later on in class.
Image Terminology• .tiff - Tagged Image File Format o .tiffs are a commonly used archival format for 2d graphics due to their support of both lossy and lossless information, as well as the ability to store other types of images inside the .tiff. This ability can also result in .tiff images being very large. o .tiff can store both raster and vector images, and are capable of working with layers.• .bmp - Bitmap Digital Image o Another type of pixel based image whose capabilities vary based on its individual properties, mostly something called Bit-depth. o Well cover bit-depth more in later classes, but know that depending on their bit depth, bit maps must either store their alpha separately or embedded within the file.
For Saturday, Feb. 9th• Be ready to ask questions on any of the previous slides or topics should you have them.• Make sure you install the TSCC Codec on your personal computer to allow you to watch the class lectures or videos again should you wish to. Well be starting to speed up from here with terms, concepts, and how to execute them, so youll want to review frequently to keep up and retain the info.