Texture Mapping

This page describes texture mapping techniques available with CreativeStudio.

For details on texture mapping, see the separate document Introduction to CTR Graphics.

The following five types of mapping are available under CreativeStudio.

Mapping Using Texture Coordinates

This mapping method uses texture coordinates.

Regardless of the size, the texture is applied within a range of 0.0 and 1.0 in both the U direction and the V direction.

Figure 1 Example Using Texture Coordinate Mapping

Mapping Using Texture Coordinates

Mapping Using Camera Cube Coordinates

This mapping method uses camera cube coordinates. This allows expressions where the surrounding scenery is reflected when the viewpoint is changed by referencing a single texture image that includes image information for each of the six directions surrounding a polygon model.

Figure 2 The Texture Used for Mapping with Camera Cube Coordinates

Camera cube coordinate texture

Figure 3 shows the result of mapping the texture in Figure 2 onto a sphere using camera cube coordinates.

Figure 3 Example of Mapping Using Camera Cube Coordinates

How to apply in camera cube coordinates

Mapping Using Camera Sphere Coordinates

When mapping textures using camera sphere coordinates, the texture is mapped based on polygon model normals and the viewpoint from the camera.

If the normals face forward as seen from the camera, the texture center is mapped there. Similarly, if normals face upward, the top part of the texture is used, and if normals face downward the bottom part of the texture is used.

This mapping method allows expressions where the surrounding scenery is reflected by referencing a single image that should be reflected by a polygon model.

Figure 4 Example of Mapping Using Camera Sphere Coordinates

How to apply in camera sphere coordinates

Mapping Using Projection

When mapping using projection, mapping is performed by projecting a texture from the appropriate camera. Projections are similar to the shadows cast by objects.

When using projection mapping, various expressions are possible including: spot lights, projection of projector-like images, and shadows.

Figure 5 Example of Mapping Using Projection

Applying in camera projection coordinates

Bump mapping

With bump mapping, you can select bump map or tangent map as the texturing method.

Bump map

Bump map is a feature that expresses virtual bumps and depressions in surfaces by slightly varying texture normals per fragment.
Because virtual bumps and depressions are expressed by a texture, you can render a model made up of a few polygons as if it were a complex model.

Figure 6 Example of Mapping Using Bump Maps

Bump map

Note: In bump mapping, the RGB values for each texel in the image are matched to the XYZ coordinates of the normal vector.
The value 128 is treated as the center value for each RGB color component. Values between 0 and 127 are treated as negative, and values between 129 and 255 are treated as positive.

Caution:
To use normal mapping, you must provide model data that includes connection attributes.
Whether model data includes connection attributes is determined when it is exported from a DCC tool (such as Maya, 3ds Max, or Softimage). This cannot be changed even by switching settings within NWCS.
For details, see the manual for each separate DCC export plug-in.

Tangent map

Tangent map is a feature that expresses virtual reflections in surfaces by slightly varying texture tangents per fragment.

Tangent mapping is mainly required for anisotropic reflections. Anisotropic reflections are reflections that exhibit directionality. They typically appear in expressions of things such as CDs and metals with a hair-line finish.

The directionality of the reflection depends on the direction of the tangent, and tangent mapping involves the shifting to the direction of the tangent.

Figure 7 Example of Mapping Using Tangent Maps

Tangent map

Note: With tangent mapping, RG values for each image pixel are matched to a tangent vector XY coordinate, an input value for the B component is not used, because tangents without a Z-component are anticipated as input.
The value 128 is treated as the center value for each RG color component. Values between 0 and 127 are treated as negative, and values between 129 and 255 are treated as positive.

Z-component recalculation

When you use the feature to recalculate the normal, the Z component is recalculated from the X,Y components (i.e., the texture's B component is not used for the vector's Z component).
In most cases, you get a better result than if you recalculated using the texture's B component.
You must enable this recalculation feature if you are going to use a HILO format texture with just R and G components for normal vector bump mapping.
However, if you choose to use tangent mapping for anisotropic reflections and the like, we recommend that you do not use this feature.
The reason is because it is presumed that tangents that do not have a Z component will be for tangent mapping of fragment lighting.


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