7_3DS Max_UV Mapping Fundamentals Flashcards
UV Mapping
The 3D modeling process of projecting a 2D image to a 3D surface for texture mapping.
It is the process for creating UV Coordinates. These coordinates tell the 3D software exactly how to cut up the texture map and where to place it on the objects.
Cluster AKA Shells
A piece of a UV map
Seam
Seams are the edges of a cluster that signify a separation from other edges in the UV coordinates
Overlapping
When polygons of a UV map overlap one another
Distortion
Distortion is an area where your texture map literally stretches or squashes on the model, skewing the texture
Texture Space
The amount of space each UV cluster has within the image size of the texture.
It’s important to balance Texture Space between all of the clusters, and to pack the clusters to use as much of this space as possible.
Texel Density
The amount of space each part of the texture has or even the UV cluster has.
Larger clusters are going to take up more texture space, thus giving them more resolution.
Packing
The process of arranging all of the clusters within the UV space.
There are two types: Automatic and Manual Packing
Automatic Packing
Arranging the clusters within the UV space using the Arrange Elements tools.
Manual Packing
Moving each cluster, rotating them, scaling them, getting them to fit in this UV space.
What are the 5 Basic UV Mapping Concepts?
- ) As few clusters as possible
- ) Minimize distortion as much as possible (it’s not possible to get rid of all distortion, know when it’s good enough)
- ) Use properly flattened overlapping UV’s, but only when necessary. Acceptable when texture is symmetrical. Not acceptable when texture is asymmetrical.
- ) Pack your UV’s efficiently while maintaining equal amounts of texel-density. Keep everything at a relative amount of resolution across the entire mesh
- ) Balance all of the concepts
What are the 4 types of Projections?
Planar, Cylindrical, Spherical, Box
Smoothing Group
Is a group of polygons in a polygon mesh which should appear to form a smooth surface.
Smoothing groups are useful for describing shapes where some polygons are connected smoothly to their neighbors, and some are not.
Planar Mapping
(First apply the Unwrap UVW in the Modifier List stack)
Projects UV’s onto a mesh through a plane. This projection is best of objects that are relatively flat, or at least are completely visible from one camera angle.
Typically done to select multiple sets of polygons, and then use that planar map projection across
Cylindrical Mapping
(First apply the Unwrap UVW in the Modifier List stack)
Creates UV’s for an object based on a cylindrical projection shape that gets wrapped around the mesh. This projection is best for shapes which can be completely enclosed and visible within a cylinder, without projection or hollow parts.
Spherical Mapping
(First apply the Unwrap UVW in the Modifier List stack)
This will project a texture inwards from a sphere. The texture will resemble the original image the most at the equator. The texture will start to converge as it reaches the poles of the sphere.
Box Mapping
(First apply the Unwrap UVW in the Modifier List stack)
This will project a texture of six sides of a cube in towards a 3D model. A texture will be projected from aside of the cube until stretching occurs, then the next best projection side will take over. Box mapping is a quick and easy solution that will work in most cases because there will be minimal stretching of textures.
Mixed Mapping
(First apply the Unwrap UVW in the Modifier List stack)
Whenever we use just a single type of projection type it will give us one type of behavior. Mixed Mapping is done so that one can mix to get the exact UV configuration desired.
Linear Align
Averages out the extent of the selection, then moves the vertices along that edge, somewhat like a constraint.
What are the two types of brushes in the UVW Editor?
UV Paint Movement
UV Relax by Polygon Angles
UV Paint Movement Brush
Controlled by the strength (inner circle of the brush) and falloff (outer circle of the brush). The fallout has different modes: fast, slow, smooth, linear
UV Relax by Polygon Angles
Ability to relax by edge angles and centers. Similar to the relax tools except with the behavior of using a brush. This can be very helpful whenever trying to relax just certain areas. Good place to use this is on a character’s face, on the nose. The nose is a very complex shape on characters and that area can get really distorted when trying to relax that area to try and remove any overlapping faces, this is the brush that will really help.
What does it usually mean if there’s an odd result in the UVW Editor?
The UV has been flipped
Explain the 5 types of Stitching options -
Stitch to Target Stitch to Average Stitch to Source Stitch to Custom Stitch Settings
Stitch to Target: Red Source side will connect to the location of the Source’s side.
Stitch to Average: Works well whenever clusters are arranged in close proximity of one another. Extends the polygons of both objects to move equal amounts towards each other.
Stitch to Source: Blue Target side will connect to the Red Source side
Stitch to Custom: Ability to align and scale clusters based on a bias value.
Stitch Settings: Available from the Stitch: Custom flyout. Opens the Stitch Tool dialog.
What color is Source vs Texture
Source is Red
Target is Blue
After adjusting, stitching, and welding a UV map, it’s common practice to do what after?
Relax the objects and make sure there are the least amounts of seams.