Development Tips - Suzie1/ComfyUI_Guide_To_Making_Custom_Nodes GitHub Wiki

Here a few tips to help accelerate your node development

ChatGPT

GPT is amazing tool for helping write functions.

Here is an example prompt used in Tutorial #4:

write a python function to draw centered text on a colored background using the PIL library
use the following input parameters
image_width, image_height, text, font_size, font_color, background_color

Here is the GPT3.5 output:

from PIL import Image, ImageDraw, ImageFont

def draw_centered_text(image_width, image_height, text, font_size, font_color, background_color):
    # Create a new image with the specified dimensions and background color
    image = Image.new("RGB", (image_width, image_height), background_color)
    draw = ImageDraw.Draw(image)

    # Load a font (you can adjust the font path as needed)
    font = ImageFont.load_default()

    # Calculate the position to center the text
    text_width, text_height = draw.textsize(text, font)
    x = (image_width - text_width) // 2
    y = (image_height - text_height) // 2

    # Draw the text on the image
    draw.text((x, y), text, font=font, fill=font_color)

    # Save or display the image
    image.save("centered_text_image.png")
    image.show()

Prototyping

  • A prototype node is a node that contains the class structure and INPUT_TYPES, and just enough code to produce a valid ouput
  • It doesn't include library imports, the main function logic or any sub-functions

For example a prototype for the node in Tutorial #4 would look like this:

class HelloWorldProtoType:

    @classmethod
    def INPUT_TYPES(cls):
               
        return {"required": {
                    "image_width": ("INT", {"default": 512, "min": 64, "max": 2048}),
                    "image_height": ("INT", {"default": 512, "min": 64, "max": 2048}),        
                    "text": ("STRING", {"multiline": True, "default": "Hello World"}),
                    "font_size": ("INT", {"default": 50, "min": 1, "max": 1024}),
                    "font_color": (["white", "black", "red", "green", "blue", "yellow"],),
                    "background_color": (["white", "black", "red", "green", "blue", "yellow"],),
                    }
                }

    RETURN_TYPES = ("IMAGE",)
    FUNCTION = "draw_overlay_text"
    CATEGORY = "Tutorial Nodes"

    def draw_overlay_text(self, image_width, image_height, text, 
                   font_size, font_color, background_color):

        return (image_out)
  • The protype node will display in UI and can be connected to other nodes, but will not be fully functional
  • It can be used for making mockups of nodes for discussion with collaborators before committing to a final design
  • In this example it will be possible to connect the prototype node to a Preview Image node, but an error will be produced in the workflow is run
name 'image_out' is not defined

image