ComfyUI Nodes Explained: Build a Workflow, Add a LoRA, Fix Missing Models (Part 3)

The ComfyUI canvas, explained for beginners. See where ComfyUI keeps your models, what every node does, how a VAE works, and how to build a Z-Image workflow from an empty canvas. Then bypass and group nodes, add a LoRA, use the official ComfyUI templates, fix missing inputs and models, manage drive space, test SageAttention properly, pick the right GPU, turn any workflow into a simple app with the Cosyflow Editor, automate it with the local API, and run a local AI chat model (Qwen 3). Measured on an RTX 5090 laptop: about 15 seconds per Z-Image picture from the ComfyUI tab and about 7 seconds per picture from an API batch. SageAttention made both Z-Image (15 → 38 s) and LTX (81 → 92 s) slower on this PC. Qwen 3 wrote three video prompts in about 90 seconds. CHAPTERS 0:00 ComfyUI Tutorial for Beginners 0:30 What Is a ComfyUI Workflow? 1:14 The ComfyUI Canvas Inside Promptus 2:06 ComfyUI Model Folders Explained 2:48 ComfyUI Nodes Explained 4:00 How a VAE Works 4:36 How to Read Links and Outputs 5:09 How to Build a ComfyUI Workflow from Scratch 6:11 How to Edit a ComfyUI Workflow 6:41 ComfyUI Bypass and Group Nodes 7:29 How to Use a LoRA in ComfyUI 8:17 Open a CosyTemplate in ComfyUI 8:40 How to Use Official ComfyUI Templates 9:36 Fix ComfyUI Missing Models 10:20 Manage ComfyUI Models and Space 10:54 Does SageAttention Make ComfyUI Faster? 11:47 How to Choose Which GPU ComfyUI Uses 12:15 ComfyUI Workflow to Simple App 12:57 ComfyUI API Automation 13:46 How AI Agents Can Use Promptus 14:03 How to Run a Local AI Chatbot (Qwen 3) 15:03 What Is CosyClaw? 15:24 Explore, Upgrades and Help 15:40 Promptus and ComfyUI ▶ Part 1, Local AI Image Generator:    • Local AI Image Generator on Windows: Promp...   ▶ Part 3, the ComfyUI canvas:    • ComfyUI Nodes Explained for Beginners: Bui...   ▶ Full course:    • ComfyUI Full Course for Beginners (2026): ...   🔥Get Promptus: https://www.promptus.ai/?utm_source=y... Connect with Promptus 👉 Subscribe:    / @promptusai   👉 Instagram:   / promptus.ai   👉 TikTok:   / promptus.ai   👉 Website: https://www.promptus.ai?utm_source=yo...    • #1 Open-Source AI Video Model Is Finally H...   #Flux2 #comfyui #promptusai #aiworkflow #comfyuiworkflow #AIVideo #AICreators #MachineLearning #generativeai #aiart #aitools #techtutorial