sxtools-blender

This project has been superceded by SX Tools 2

NOTE: Please visit the new Documentation Site This readme is partially out of date.

For Game Developers

SX Tools is a lightweight content pipeline for vertex-colored assets that drive PBR (Physically Based Rendering) materials in a game. This tool ships with baseline shader networks for Unreal and Unity.

For 3D Artists

SX Tools is a multi-layer vertex coloring toolbox, referencing a workflow from common 2D image editing programs.

Highlights

For game artists, UV-channels are presented as grayscale layers. Regular paint operations like gradients, color fills and even occlusion baking can be performed directly to UVs like they were vertex color layers. The toolbox comes with a custom material that displays all edits in the viewport in realtime.

The artist can therefore apply per-vertex occlusion/metallic/smoothness/transmission/emission directly on the model, and tweak the results interactively.

Features

Multi-layer vertex color editing
Layer blend modes (alpha, additive, multiply, overlay)
Color filler with optional noise
Color gradient tool with optional noise
Curvature-based shading
Vertex ambient occlusion baking
Mesh thickness baking
Luminance-based tone-mapping
Master Palette Tool for quickly replacing the color scheme of object/objects
PBR Material Library
Quick-crease tools
Modifier automations
Material channel editing via UV channel values (subsurface scattering, occlusion, metallic, roughness)
FBX-exporting multi-layer vertex-colors to game engines via UV channels to drive the standard PBR material

Installation:

Download the zip file, uncompress it, then install and enable sxtools.py through the Blender add-on interface
Point the library folder in SX Tools prefs to the unzipped folder
SX Tools will appear in the top right corner of the 3D view
Open the Misc-tab in the top right corner of the 3D View, pull the tab in from side of the screen

Getting Started:

Now would be a good time to visit the new Documentation Site

Point SX Tools to the folder where the zip was uncompressed. This also contains example palettes, PBR materials and gradient presets.

Create and select a mesh object.
Enable the layers and channels you wish to work on. These settings are scene-specific.
Alpha and RGBA overlays are for very specific needs in game projects, it is recommended not to enable them unless necessary. The Layer View refers to Alpha Overlays as Gradient1 and Gradient2.
Choose "Erase Existing UV Sets" if you are creating a new mesh object. If you are working with an object with existing UV data, uncheck this option and SX Tools will attempt to preserve existing UV sets if there are enough slots available for the selected options.
Click on Set Up Object. SX Tools will now generate the needed layers, UV sets, variables and a custom material

The default view of SX Tools is now active. Think of your favorite 2D paint tool. Click on layers, apply colors to objects or components, get familiar with the available tools.

After some familiarization, you'll be able to create rapid color variants of your game assets in no time.

Exporting to Game Engines

The basic flow for using SX Tools in game development is as follows:

Model your assets as low-poly control cages for subdivision
Define the categories needed for your objects in your game
Set up project in SX Tools, enable the needed features
Assign objects to categories
Color the objects according to category-specific layer definitions
Batch-process the objects for export, leave as much work for automation as possible. Take a look at the existing batch functions and adapt to your project needs.
Export to your game engine as FBX
Run the assets using a the provided custom material (or make your own)

The package contains simple example shader graphs for Unreal4, and both HDRP and LWRP renderers in Unity 2019. Dynamic palette changes in the game engine are not facilitated by the example shader graphs, but they do fully support driving PBR material channels with UV data.

Currently the export channels are set in the following way:

Channel	Function
UV0	Reserved for a regular texturing
U1	Layer coverage masks for dynamic palettes
V1	Ambient Occlusion
U2	Transmission
V2	Emission
U3	Metallic
V3	Smoothness
U4	Alpha Overlay 1, an alpha mask channel
V4	Alpha Overlay 2, an alpha mask channel
UV5/UV6	RGBA Overlay, an optional additional color layer
UV7	Currently not in use

Vertex colors are exported from the Composite/VertexColor0 layer. Material properties are assigned according to the list above. Note that emission is only an 8-bit mask for base vertex color, not a full RGBA-channel.

Acknowledgments

Thanks to:

Rory Driscoll for tips on better sampling

Serge Scherbakov for tips on working with iterators

Jason Summers for sRGB conversion formulas

SX Tools builds on the following work:

Vertex-to-edge curvature calculation method

Algorithm by Stepan Jirka

http://www.stepanjirka.com/maya-api-curvature-shader/

Integrated into SX Tools under MIT license with permission from the author.

V-HACD For Blender 2.80

Add-on by Alain Ducharme (original author), Andrew Palmer (Blender 2.80)

https://github.com/andyp123/blender_vhacd

SX Tools detects the presence of the V-HACD add-on and utilizes it for mesh collider generation.

FrandSX/sxtools-blender