New hsv() driver

Adding hsv(h, s, v, 0) driver and updating documentation along with sample project

README.md

@@ -1,14 +1,19 @@
-# VF-BlenderDriverFunctions
+# VF Driver Functions
 Functions for use in Blender channel drivers.
 
-Installation and usage:
-- Download the .py file
-- Open up Blender preferences
-- Install the addon
-- Enable the addon
+
+
+## Installation and usage:
+- Download the desired driver
+ - [VF_curveAtTime.py](https://raw.githubusercontent.com/jeinselenVF/VF-BlenderDriverFunctions/main/VF_curveAtTime.py)
+ - [VF_hsv.py](https://raw.githubusercontent.com/jeinselenVF/VF-BlenderDriverFunctions/main/VF_hsv.py)
+ - [VF_wiggle.py](https://raw.githubusercontent.com/jeinselenVF/VF-BlenderDriverFunctions/main/VF_wiggle.py)
+- Open up Blender Preferences > Add-ons
+- Install and enable the add-on
 - Add a driver to any channel via keyboard shortcut (usually "D"), context menu (right-click), or directly (typing "#" and then the function)
 
 
+
 ## curveAtTime
 This driver function is intended to mimic Adobe After Effect's "valueAtTime" expression, returning the value of an animated channel from the specified point in time.
 
@@ -37,6 +42,19 @@ Note that Blender's time sampling doesn't allow references to an object's transf
  - Note how the current frame value is multiplied by 0.5 to slow down time
 
 
+## hsv
+Converts from HSV value inputs to RGB value outputs. Because drivers are designed for individual channel usage, the specific red (`0`), green (`1`), or blue (`2`) channel output must be selected.
+
+The following example uses the `X`, `Y`, and `Z` positions of a controller null to drive the `hue`, `sat`, and `val` variables within the driver, and the same driver setup is copied across all three `r`, `g`, and `b` input channels in both the material, updating the fourth value (`0`, `1`, or `2`) to match the channel index.
+
+```javascript
+hsv(hue, sat, val, 0)
+```
+
+Download the example project: [hsv.blend](images/hsv.blend.zip)
+
+![screen capture of the Blender interface showing both the controller null and the driver function applied to the red channel of an affected object](images/hsv.png)
+
 ## wiggle
 Designed to mimic Adobe After Effect's "wiggle" expression with similar frequency (colloquially known as wiggles per second) and octave settings.
 

VF_hsv.py

@@ -0,0 +1,48 @@
+bl_info = {
+ "name": "VF Driver HSV",
+ "author": "John Einselen - Vectorform LLC",
+ "version": (0, 1),
+ "blender": (2, 80, 0),
+ "location": "Channel driver -> hsv(0.1, 0.5, 1.0, 0)",
+ "description": "Adds hsv(hue, saturation, value, RGB channel output) driver function",
+ "warning": "inexperienced developer, use at your own risk",
+ "wiki_url": "",
+ "tracker_url": "",
+ "category": "Rigging"}
+
+# Thanks for the help:
+# https://blender.stackexchange.com/questions/71305/how-to-make-an-addon-with-custom-driver-function
+# https://blender.stackexchange.com/questions/80034/hsv-to-rgb-conversion
+
+# Example usage:
+# hsv2r(0.5, 1, 1, 0)
+# this will convert HSV input values into RGB output values, and return the first (red) channel
+
+import bpy
+from colorsys import hsv_to_rgb
+from bpy.app.handlers import persistent
+from bpy.app import driver_namespace as dns
+
+def hsv(h, s, v, c):
+ color = hsv_to_rgb(h, s, v)
+ if c < 0.5:
+ return color[0]
+ elif c < 1.5:
+ return color[1]
+ else:
+ return color[2]
+
+@persistent
+def load_handler(dummy):
+ dns = bpy.app.driver_namespace
+ dns["hsv"] = hsv
+
+def register():
+ load_handler(None)
+ bpy.app.handlers.load_post.append(load_handler)
+
+def unregister():
+ bpy.app.handlers.load_post.remove(load_handler)
+
+if __name__ == "__main__":
+ register()