Manual/Map Input

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User Manual: Contents | Guidelines | Blender Version 2.45

Texture Map Input

Description

Textures needs mapping coordinates, to determine how they are applied to geometry. The mapping specifies how the texture will ultimately wrap itself to the object. For example, a 2D image texture could be configured to wrap itself around a cylindrical shaped object.

Examples

Conceptual texture pipeline

(Conceptual texture pipeline) is what is happening if you could "see" each panel(s) associated with each texture or image at the same time. However, only one panel is visible at any one time. To change a texture's Map Input properties you must first select the texture on the Texture panel.

Position a Decal on a Mesh

Another common use of Map Input, briefly mentioned above, is placing a decal somewhere on a mesh:

• Insert an Empty into your scene, positioned close to the surface of your mesh where you want the center of the decal to be, and oriented with its X-Y axis as you want your decal to appear (the Z axis should point away from the mesh, i.e. normal to the mesh).
• Assign an image texture to the mesh, loading the decal image, and set UseAlpha and ClipCube in the Map Image panel.
• In the Map Input field, select Object and in the blank field to the right of the button, enter the name of the Empty, which by default is "Empty"

In the example to the right, an Empty named "Decal" is just above the surface of the red ball, with the Z pointing away from the ball. In the material settings for the ball, an image of an arrow is mapped to the location and XY orientation of the empty.

You may Scale the empty to make the decal larger or smaller, and/or use the Size sliders in the Map Input panel. You can tweak the position of the decal by moving the empty or using the Offset sliders.

Hints

When choosing a mapping style consider the following questions:

• What is the source of the input Coordinates?
• Where is the top left corner?
• Where does the Texture begin?
• How large is the Texture and how often does it have to be repeated?
• Do we have multiple points to begin the texture, like at a cube?
• Will the Texture be rotated?

Mapping an image to the Window coordinates will cause the image to be tiled across the surface, without stretching, facing the camera without regard to the object's geometry.

Global coordinates, when mapped to Cube, tile the virtual space with the image. Wherever the object happens to be, it gets the texture that exists in that space.

Textures scale along with the object. If you scale an object larger, the image or procedural texture is scaled up as well. To make more patterns of the texture repeat across the surface, either increase the image repeat value (if an image) or increase the SizeXYZ values in the Map Input panel. This can be a pain if you have a texture such as a brick, and you make the wall longer; the bricks will stretch out. You can either use a procedural plug-in texture that figures out the repeats for you, or get out the calculator and divide the "true" texture size by the actual wall size to determine how many repeats there should be.

Use multiple texture channels of the same texture, each Sized differently, to create the natural patterns found in nature (principle of the fractals).

To make them completely independent from the object's scale, either use Global mapping or Object, referencing an empty at the object's center with a scale of 1 (preferably parented to the object if you are animating it.).

Input Source

Description

Mapping works by using a set of coordinates to guide the mapping process. These coordinates came come from anywhere, usually the object to which the texture is being applied to.

For UV or Object mapping, enter the name of the UV Texture or Object that you want to use as the orientation for the texture in the little blank field immediately to the right of the UV and Object buttons. The default name for a UV Texture is "UV Tex"; the exact name is found in the Materials panels where the UV Textures are listed. You can only specify one UV Texture for each mapped Texture image. If you want to layer UV Textures, you have to use multiple channels. See UV Unwrapping for more information on using UV Textures.

Options

Map Input Panel

UV

UV mapping is a very precise way of mapping a 2D texture to a 3D surface. Each vertex of a mesh has its own UV co-ordinates which can be unwrapped and laid flat like a skin. You can almost think of UV coordinates as a mapping that works on a 2D plane with its own local coordinate system to the plane on which it is operating on. This mapping is especially useful when using 2D images as textures, as seen in UV Mapping. You can use multiple textures with one set of UV Co-ordinates.

To use a UV map to guide the texture placement, click UV and enter the name of the UV Texture in the input field. The name must match exactly and is case-sensitive. If the name does not match one of the existing UV Textures, the field will be red.

Then, for the Color of the texture, map the image texture to Col (if the image is the color/diffuse image). Map to Nor if the image is the bump map, etc. See Bump and Normal mapping for more info on those special kinds of images. See the next page for more info on Map To panel.

Object

Uses a child Object's texture space as source of coordinates. The Object name must be specified in the text button on the right. Often used with Empty objects, this is an easy way to place a small image as a logo or decal at a given point on the object. This object can also be animated, to move a texture around or through a surface

Glob - Global

The scene's Global 3D coordinates. This is also usefull for animations; if you move the object, the texture moves across it. It can be useful for letting objects appear or disappear at a certain position in space.

Orco - Original Coordinates

"Original Co-ordinates" - The object's local texture space. This is the default option for mapping textures.

Stick

Uses a mesh's sticky coordinates, which are a form of per-vertex UV co-ordinates. If you have made Sticky co-ordinates first (F9 Mesh Panel, Sticky Button), the texture can be rendered in camera view (so called "Camera Mapping").

Win - Window

The rendered image window coordinates. This is well suited to blending two objects.

Nor - Normal

Uses the direction of the surface's normal vector as coordinates. This is very useful when creating certain special effects that depend on viewing angle

Refl - Reflection

Uses the direction of the reflection vector as coordinates. This is useful for adding reflection maps - you will need this input when Environment Mapping.

2D to 3D Mapping

Description

The Image texture is the only true 2D texture, and is the most frequently used and most advanced of Blender's textures. Because images are two-dimensional, the way in which the 2D texture coordinate is translated to 3D must be specified in the mapping buttons.

Options

Depending on the overall shape of the object, one of these types may be more useful than others.

If the UV button (see #Input Source; Others also?) is enabled you can imagine all these buttons except for the Flat button to be disabled.

Flat Mapping.

Flat

Flat mapping gives the best results on single planar faces. It does produce interesting effects on the sphere, but compared to a sphere-mapped sphere the result looks flat. On faces that are not in the mapping plane the last pixel of the texture is extended, which produces stripes on the cube and cylinder.

Cube Mapping.

Cube

Cube mapping often gives the most useful results when the objects are not too curvy and organic (notice the seams on the sphere).

Tube Mapping.

Tube

Tube mapping maps the texture around an object like a label on a bottle. The texture is therefore more stretched on the cylinder. This mapping is of course very good for making the label on a bottle or assigning stickers to rounded objects. However, this is not a cylindrical mapping so the ends of the cylinder are undefined.

Sphere Mapping.

Sphere

Sphere mapping is the best type for mapping a sphere, and it is perfect for making planets and similar objects. It is often very useful for creating organic objects. It also produces interesting effects on a cylinder.

Co-ordinate Offset, Scaling and Transformation

Description

For extra control, the texture space can also be tweaked, to move, scale and flip the apparent texture on its axes

Options

Map Input Panel

ofsX, ofsY, ofsZ - Offset

The texture co-ordinates can be translated by an offset. Enlarging of the Ofs moves the texture towards the top left.

sizeX, sizeY, sizeZ - Size

The scale of the texture space. Enlarging the texture space will make the apparent texture scale smaller. The texture is as often repeated (if set up as repeating) as sized here.

[ ], X, Y, Z (x3) - Axes

Re-orders the X, Y and Z coordinates. You can flip axes to mirror a texture, or ignore axes all together.

3D View texture space transform

Description

The texture space can also be transformed interactively in the 3D View, just like moving or scaling an object. This determines the area that the texture uses to define its co-ordinates.

Options

Texture Space popup menu

Press T while an object is selected to get the Texture Space popup menu. The following options are available:

Grab/Move

Moves the objects' texture space

Scale

Scales the object's texture space

Scaled Texture Space box.