Texture Generation

With texture generation you produce a tileable wall, floor, path, staircase or roof material from a small set of models. One layout gives an albedo map, a lit albedo map, a normal map and an ambient occlusion map at the same time. The result is a normal Unity material.

A texture definition is the asset that drives the process. PolyBash arranges its block prefabs into a layout, renders that layout through an orthographic capture, and writes one image per capture type. The process creates no scene object.

This page explains the four texture definitions and every section of their inspector. The page Surface Variants explains the color variation that a capture applies.

Concepts

• Texture definition: the asset that holds every setting. It describes the layout, the capture and the output.
• Block: one instance of a prefab in the layout. A layout contains many blocks.
• Layout: the arrangement of blocks that PolyBash generates from the placement settings and a random seed.
• Capture: one render of the layout into one image. Each capture type produces its own image.
• Preview: a live render into RenderTexture assets. A preview never writes an image file.
• Finalized textures: the PNG files that PolyBash writes when you capture to disk.

Create a texture definition

1. In the Project window, select the folder that must contain the asset.
2. Select Assets → Create → Snowtop → PolyBash, and then select one texture definition.
3. Name the asset.

All four texture definitions share the same capture settings, and they differ only in the Layout section. The stair texture definition renders the staircase along its slope. PolyBash rotates the layout by 45 degrees for the capture, so that the treads and the risers fill the image.

Included block prefabs

PolyBash includes the block prefabs of every texture definition. The prefabs are in the folder Assets/Snowtop/PolyBash/Texture Generation/Prefabs, with one subfolder per set.

Each prefab holds one mesh and one Normal Texture Config component. The component references the normal map beside the prefabs, such as Blocks-1m-Brick_Normal.png. As a result, a Normal capture shows the surface detail of the blocks without any texture from you.

Drag a whole folder into the Prefabs list to add every prefab of one set at the same time.

You can edit the included prefabs. Copy a prefab before you edit it, so that an update of PolyBash does not overwrite your changes. Then add the copy to the Prefabs list.

Included texture definitions

PolyBash includes nine texture definitions of three types in the folder Assets/Snowtop/PolyBash/Texture Definitions. The sample scene uses the textures that these texture definitions produce.

• Wall texture definitions: WallTextureDefinition, FloorTextureDefinition, TrimTextureDefinition and WoodPathTextureDefinition.
• Roof tile texture definitions: RoofTileTextureDefinition, RoofTileTextureDefinition2, WoodBlueSidingTextureDefinition and WoodRedSidingTextureDefinition.
• Stair texture definition: StairTextureDefinition.

Every included texture definition writes its images into the folder Assets/Snowtop/PolyBash Samples/GeneratedTextures. As a result, a capture of an included texture definition replaces the textures of the sample.

To keep the sample unchanged, duplicate the texture definition, and change the Output Folder of the copy. Then select Recreate assets at canonical path in the copy, so that the copy creates its own material.

Workflow

1. Prepare the block prefabs. Each prefab needs one mesh on its root GameObject, and the section Included block prefabs describes the included prefabs.
2. Create the texture definition.
3. Add the prefabs to the Prefabs list in the Layout section.
4. Configure the row count, the dimensions and the block sizes.
5. Select Capture Preview, and then inspect each tab of the Preview section.
6. Add at least one surface variant in the Texture Generation foldout, because the included prefabs carry no material of their own.
7. Configure the resolution, the padding and the output folder.
8. Select Capture to Disk.

PolyBash writes the images, imports them, and points the material at them, so you can assign that material to any renderer.

Layout

The Layout section holds the placement settings of the texture definition. These fields control the arrangement of the blocks, and never the capture itself. Every texture definition shares these fields:

The wall texture definition and the path texture definition add these fields:

The stair texture definition adds these fields:

The roof tile texture definition adds these fields:

Row offsets accumulate with alternating signs, and PolyBash wraps each row at the edge of the layout, so that the result still tiles horizontally. Each tile of the roof texture definition hangs from the top of its row. As a result, a tile that is taller than the row pitch covers the row below.

Texture Generation

The Texture Generation foldout controls the appearance of the captures, and it contains five groups.

Lighting (AlbedoLit)

These fields apply only to the AlbedoLit capture, which bakes one directional light into the color.

Background Textures

When you assign a background texture, PolyBash draws a quad behind the blocks, and the quad fills the areas where no block covers the image.

When you assign no background texture, the background color of the Background section fills the area instead.

Normal Capture

For a layout that tilts every block in the same direction, such as a roof, select Include Geometry, and then select Level Block Tilt. The roof then looks like a flat surface, and the shape of each tile stays visible.

Ambient Occlusion

Use Normal Maps reads the surface directions from the finished normal capture, and not from the geometry. That capture contains the facing of the blocks only when Include Geometry is selected and Geometry Strength is above 0. Otherwise the occlusion treats every face as if it looks straight at the viewer, and only the detail of the normal maps remains.

The wrap options assume that the padding on the matching axis is 0. For a stylized surface that uses no lighting at run time, select Bake Into Albedo.

Surface Variants

This group recolors the blocks. The page Surface Variants documents the list, the entry fields and the Random Seed field below the list.

Resolution

Resolution sets the size of the longer side of the image, from 256 to 4096 pixels. PolyBash derives the shorter side from the proportions of the layout, plus the padding. A wide layout produces a wide image, and no capture distorts the blocks.

Background

Change Normal Background only when you understand the encoding of a normal map, because the default value describes a flat surface.

Padding

Padding adds empty space around the layout, in meters. The four fields are Padding Left, Padding Right, Padding Top and Padding Bottom.

Keep every padding value at 0 for a texture that must tile. Any padding places a border in the image, and that border breaks the repetition.

Output

Material

PolyBash creates the material with the default lit shader of the active render pipeline. You can also assign a material that you already use, and the capture then drives that material instead.

Use Recreate assets at canonical path after you rename the texture definition or change the output folder. The previous files stay on disk, and every reference to them stops receiving updates.

Preview

The Preview section shows the live captures, with one tab per capture type. The Occlusion tab appears after the first occlusion capture.

PolyBash captures the preview again after you change a field of the Layout section or of the Texture Generation foldout. After a change in another section, select Capture Preview.

When the Material field holds a material, an edit of a surface variant asset that the texture definition uses also triggers a new capture.

Lifetime of the preview textures

Unity discards the preview RenderTextures when you save the scene, and when the scripts recompile. The preview tabs then appear empty, and a material in Preview mode loses its textures. The loss is never permanent: select Capture Preview, and then select Preview in the Material section, and the live preview returns.

Use the preview while you adjust the settings, and select Capture to Disk after you finish. The saved images are permanent files in your project, and the material then reports the mode Finalized.

Capture Actions

Capture to Disk renders every capture type, writes the images to the output folder, and points the material at them. The Material section then reports the mode Finalized.

Capture Info

This section reports the size and the center of the layout, in meters. Use these values to verify the dimensions before a capture.

The values come from the moment when the inspector opened, and a change of the layout does not update them. To update the values, select another asset, and then select the texture definition again.

Capture types

Every capture of a texture definition renders all of these capture types, although the Occlusion capture type needs Capture Occlusion.

The capture shaders Snowtop/PolyBash/Capture/* appear in the Shader menu of every material. PolyBash uses them only to capture, preview and bake textures, so do not assign them to a material.

Generated files

A capture creates these assets, where <name> is the File Name, or the name of the texture definition asset:

PolyBash applies the import settings for you: it imports the normal map as a Normal Map texture, and it disables sRGB on the occlusion map. On the High Definition Render Pipeline, PolyBash writes the occlusion into the green channel of a mask map.

Capture works only in the Unity Editor, so a player build cannot run it.

To assign the material to a spline generator, use the Texture Definition Applier component. The section Texture Definition Applier of the overview page describes that component.

Normal maps of the blocks

The Normal capture combines three contributions, and each one is optional, so a block can use any combination.

1. The normal maps of the prefab, from a Normal Texture Config component.
2. The normal that is paired with a surface variant, from the Target Normal field of the asset.
3. The facing of the block itself, from Include Geometry.

For the first contribution, add a Normal Texture Config component to the root GameObject of the block prefab, next to its Mesh Renderer. The component provides these fields:

Seeds

A texture definition holds two independent seeds:

• Random Seed in the Layout section controls the arrangement, the normal map of each block, and the random per-block offset of the target texture.
• Random Seed below the Surface Variants list controls the colors.

You can change the colors without a change of the arrangement. The same pair of seeds always reproduces the same result.

Tileable results

Follow these rules for a texture that repeats without a visible seam:

1. Keep every padding value at 0.
2. When you capture occlusion, select Wrap Horizontal and Wrap Vertical.
3. Verify that each texture of a surface variant uses the wrap mode Repeat.

All four texture definitions wrap their row offsets or step offsets at the layout edge, so the rows still align across the seam.

Troubleshooting