VBLEND TILE is specially designed to work with cylindrical maps to create textures that tile seamlessly in both directions. It takes advantage of the fact that when a texture rendered as a cylindrical
texture map is used as a planar map, it tiles perfectly in the horizontal direction. Therefore, VBLEND TILE only modifies the Background to tile vertically. VBLEND TILE will do the best job on textures that work
well as cylindrical maps.
VBLEND TILE only has two parameters, the Background texture that is to be tiled and the Blend_Width. The Blend_Width parameter defines the width of the blend region from the top of the texture to the
center and from of the bottom of the texture to the center. A Blend_Width of 0% eliminates the blend region and the Background texture won't tile. A Blend_Width of 100% will blend all the way to the center
of the tile.
Keep in mind that a tileable texture created with VBLEND TILE needs to be rendered out as a cylindrical
map, otherwise, it won't tile in the horizontal direction at all. When rendering a cylindrical map that is to be used as a planar map, you get the best results when the texture map is approximately three times as
wide as it is high, 300x100 pixels, for example. This is because a cylinder's diameter is about this much larger than its height. You can try different width/height ratios to vary the amount of squeezing and
stretching of the cylindrical map in the X-direction. You can also scale the texture being tiled along the z-axis to get rid of any squeezing.
A very important rule about the VBLEND TILE component is that it will not work if the component's transform has been modified in any way, whatsoever. If a VBLEND TILE component has a parent texture,
the act of changing the transform of the parent texture may indirectly modify the transform of the VBLEND TILE texture. The VBLEND TILE's transform can be cleared by selecting the "Clear" button in
the Transforms area of the VBLEND TILE component editor. If a texture doesn't seem to be tiling correctly, this is probably the cause.
Any area of the texture that is outside the valid tile region will show up as a grayscale check pattern for
color and percent textures and as completely flat for bump textures. If these "invalid" regions appear in any of the texture previews, it indicates that the VBLEND TILE component's transform needs to be cleared.
Linking the Blend_Width to a percent FRACTAL noise component with its Low and High parameters set to reasonable blend width values can sometimes improve the quality of the tile by breaking up the blend.
When using the Basic_Shader component to make a fully shaded, tileable texture, you will get much
better results if you tile the different attribute textures (color, luminosity, bump, etc) individually instead of just tiling the Basic_Shader itself. If you just tile the Basic_Shader, the specular highlights and
reflective areas of the shaded texture are blended across tiles which doesn't look realistic. If the attributes are blended/tiled before being shaded, specular highlights and reflective areas are calculated correctly.
