Spritehandler

by Benjamin Morrison in Scripts and Addons

Spritehandler

Recent Updates (1.6, 28/2/2019)

  • Convert image atlases to individual meshes. New meshes based on alpha matte to minimize overdraw.
  • Adjust output scale of generated sprite sheets

Spritehandler is a set of tools for using, and generating, sprite sheets within Blender. Using a node group to manipulate UV coordinates, Spritehandler sequences sprite sheets loaded through image texture nodes. This opens up a wealth of possiblities for rendering sprites, flipbooks, billboards, particles, and material variations. All functionality is wrapped in intuitive operators for efficiency and ease of use


Playback of Spritesheets and Flipbooks

Spritehandler’s core function is to enable the use of sprite sheets within material nodes. Creation of sprite planes through the operator will setup a time node, removing the need to keyframe playback.

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Particles, Static and Animated

Using the Spritehandler node group with particle systems greatly expand what is possible with Blender’s limited particle rendering tools.

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Material Variations with Atlases

By driving the node groups index function with object data or randomization, spritehandler can be used to create complex material variations across instances.

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Packing

Spritehandler can also be used for simple sprite packing using either on-disk images or packing automatically from render output.

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Atlas to Mesh

Convert atlas maps to mesh objects based on their grid layout and alpha channels.

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Features

  • Demo files
  • Preset based sprite plane creation
    • Playback
    • Particle Indexing
    • Particle Playback
    • Billboard Toggle
    • Setup operator for planes
  • Playback Control
    • Delay start
    • Speed
    • Index Offset
    • Total offset (for uneven sheets)
    • Loop limits
  • Current frame shader node
  • Render farm/distributed rendering compatible
  • Generate spritesheets from images
  • Generate spritesheets from animation render
  • Adjust scale of generated spritesheets
  • Convert atlas images to individual, grouped, meshes with alpha derived topology

Usage


Nodegroup Parameters

  • Index : Current index to output.
  • Start Delay : Delay playback / freeze playback until this frame is reached.
  • Index Offset : Offset the current index.
  • X Cells : Total number of horizontal cells.
  • Y Cells : Total number of vertical cells.
  • Adjust Total : Adjust total cell count for uneven cell sheets.
  • Loop Count : Playback limits.

Tutorial: Sprite Planes

  1. Add Menu (SHIFT+ A) > Mesh > Create New Sprite Plane
  2. Select Spritesheet file and choose a host type/Preset:
    • Animated : Index driven by current frame
    • Static : Index driven by random number
    • Particle Animated : Index driven by particle age
    • Particle Static : Index driven by particle index
  3. Setup sheet by either:
    • Running operator: Object > Setup Spritesheet
    • Manually set the group node parameters and run operator: Object > Scale From Sprite Node

Tutorial: Sprite Packing

Sprite packing is performed through the Spritesheet Generator Toolshelf in the UV/Image Editor

  • Generate Spritesheet prompts to user to select sprites for packing and then generates an new sheet from them based on the 'X Cell Count'
  • Regenerate Spritesheet last images used in Generate Spritesheet and repacks based on the 'X Cell Count'
  • Enabling Sheet from Render will generate a spritesheet from animation renders. These sheets can also be used with Regenerate Spritesheet

Tutorial: Atlas to Mesh

  1. Add Menu (SHIFT+ A) > Particle Atlas to Mesh Group
  2. Set creation parameters using the operator properties(Bottom left corner of 3d view)
    • Sheet Path : Atlas for conversion
    • Cells : Set atlas cell values
    • Subdivision : Controls the accuracy of the conversion
    • Dilate Alpha : Grows the alpha of each cell
    • Un-Subdivide : Enable/Disable mesh optimization
    • Decimate Factor : Number of optimization steps
    • Triangulate : Triangulate final meshes
    • Group : Create a new group and add mesh to it
    • Individual Group : Create, and apply, a unique group for each mesh
    • Island Clean : Remove small mesh islands based on their area.
    • Surface Type : Shader type to use for the new objects' material
  3. Experiment with subdivision and alpha dilate values to get a feel for how they affect the mesh generation. Higher subdivision values are very computationally expensive and you should focus on alpha dilation to recover clipped details. Disable Un-Subdivide to better see generation process. Alpha dilation is likely to generate small floating islands that can be cleaned with the Island Clean parameter set to a low value.

Advanced Use / Materials / Manual Setup

The spritehandler node group functions by scaling UV coordinates into ranges appropriate for stepping over grid packed spritesheets/material atlases. Refer to demo files and observe how the handler nodes are being driven by their own sets of uv coordinates and masked where necessary.


Credits

Promotion materials include work from the following