You can also use a Unique UVs projection’s Angle Grouping algorithm to unfold an object’s UV coordinates. This is described in Unfolding a Texture Projection.
A Unique UVs projection’s polygon packing algorithm applies a texture to polygon objects by assigning each polygon’s UV coordinates to its own distinct piece of the texture so that no two polygons’ coordinates overlap each other. This is useful in situations where you want to apply a texture to an object without worrying about how the object should be “unfolded” over the texture.
This type of Unique UVs projection only produces good results if you use a texture created specifically for the projection. You can create such a texture by rendermapping the textured object using a Unique UVs projection.
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You can also use a Unique UVs projection’s Angle Grouping algorithm to unfold an object’s UV coordinates. This is described in Unfolding a Texture Projection. |
To create a unique UVs rendermap for an object
1. Texture a polygon object as described [here]. Select an appropriate projection type.
2. Apply a RenderMap property to the object as described [here]. Make sure to set the rendermap’s UV Coordinates to a Unique UVs projection.
3. In the RenderMap property editor, click the Edit button next to the UV Coordinates list. The PolyPackUV property editor opens.
4. Make sure that the Flattening Method is set to Individual polygon packing.
5. If desired, you can also pre-adjust the projection’s dimensions and spacing before generating the render map. This is described in the next section, Pre-Adjusting a Unique UVs Projection.
6. Generate the rendermaps. This creates a maps specifically designed for the corresponding Unique UVs projection.
Pre-Adjusting a Unique UVs Projection
Although you apply a Unique UVs projection the same way you would apply any other texture projection, you may want to adjust the projection’s properties before you use it for rendermapping your object.
To pre-configure a unique UVs projection
1. Create a unique UVs rendermap for an object, as described in the previous procedure, but do not generate the rendermap (follow only steps 1 to 4).
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You can also open the PolyPackUV property editor by clicking its node in the texturing operator stack. You can locate the node in the explorer, under the object’s hierarchy. 
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2. Adjust the following parameters in the PolyPackUV property editor to control how the object’s UV coordinates are placed on the texture image:
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The following options allow you to precisely control where an object’s UV coordinates appear on a target texture and, so they are quite useful when you are generating a single rendermap for multiple objects, as described [here]. |
- Lower Left Corner (U, V): Adjusting these values offsets the UV coordinates from the lower-left corner of the target texture. The offset is measured in UV coordinates, which are usually between 0 and 1, so a value of 0.15 offsets the coordinates by 15%.
- Dimensions (Width, Height): Adjusting these values resizes the bounding box of the UV coordinates. The size is measured in UV coordinates, which are usually between 0 and 1, so a value of 0.75 resizes the coordinates by 75%.
- Explicit Pixel Spacing specifies the resolution (in pixels) of the texture for which the UV coordinates are generated. You can also specify the minimum distance between polygons’ UV coordinates.
- Target U, V Resolution: When Explicit Pixel Spacing is selected, these values specify the resolution (in pixels) of the target texture for which the unique UV coordinates are generated.
- U, V Pixels: When explicit pixel spacing is enabled, these values specify the minimum distance, in pixels, between individual polygons' UV coordinates in U and V.
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• Spacing between polygons is important when you have the Spill into empty texels option selected in the RenderMap Property Editor [Properties Reference]. You need a spacing of at least two pixels around polygons so that each polygon can spill into the empty texels without overlapping another polygon’s spill area. • The spacing between polygons is set for an image of the size specified by the Target U,V Resolution values. This means that if you set a target resolution of 256 x 256, but then generate the rendermap at a resolution of 128 x 128, a spacing of two pixels becomes a spacing of one pixel. Conversely, generating a rendermap at a resolution of 512 x 512 turns a spacing of two pixels into a spacing of four pixels. |
- U, V: When Explicit Pixel Spacing is off, these values specify the distance between individual polygons’ UV coordinates. The distance is measured in UV coordinates.
3. When you’re ready, apply a RenderMap property to the object and generate the rendermap (see To apply a RenderMap property) using the unique UVs projection. The output texture will conform perfectly to the unique UVs projection.
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