Blender 2.82 | Cycles
The Cycles render engine in Blender has a very convenient OSL Shader development and usage workflow.
Shaders can be both loaded from external files or written and compiled directly inside Blender.
To write an OSL shader in Blender:
- Write your shader code in Blender‘s Text Editor:
- In your object’s material shader graph (Shader Editor view),
Create a Script node:
- Set the Script node‘s mode to Internal,
And select your shader’s text from the Script node‘s source drop-down:
- If the shader compiles successfully, the Script node will display its input and output parameters, and you can connect it’s output to an appropriate input in your shading graph.
* If your shader is a material (color closure) connect it directly to the Material Output node’s Surface input, is it’s a volume to the Volume input, or if its a texture to other material inputs as needed.
- If the shader code contains errors, it will fail to compile, and you’l be able to read the error messages in Blender‘s System Console window:
- After fixing errors or updating the shader’s code, press the Script Noe Update button on the Script node to re-compile the shader:
Loading an external OSL shader into Cycles:
Exactly the same workflow described in the previous section, except setting the Script node‘s mode to External and either typing a path to the shader file in the Script node or pressing the little folder button to locate it using the file browser: