CharGen

This post is my submission for DEV Education Track: Build Apps with Google AI Studio.

What I Built

I built a Game Character Generator app using Google AI Studio’s Imagen API that creates highly detailed, original game characters based on user-selected features like appearance, weapons, abilities, environment, and art style.

The core of the app is a structured prompt system that dynamically combines user inputs (genre, character type, powers, pose, environment, etc.) into a single optimized prompt for image generation. I focused on ensuring the characters are game-ready, original, and visually consistent, avoiding copyrighted designs.

Key features used:

Imagen image generation via Google AI Studio

Advanced prompt engineering with modular feature inputs

Constraint-based prompting for originality and quality

Demo

I tested the app by generating multiple character types such as cyberpunk assassins, fantasy warriors, and sci-fi soldiers, each with different poses, moods, and environments.

👉 https://ai.studio/apps/drive/1I8BPWstKRQoeAliu1msNBKxfvFu9s7M6?fullscreenApplet=true
👉

The app demonstrates how prompt structure directly affects output quality and consistency.

My Experience

This project significantly improved my understanding of prompt engineering for image models, especially how breaking prompts into clear, descriptive sections leads to better results than long unstructured text.

What I learned:

How to design prompts that scale with multiple user-controlled features

How constraints (like “original design only”) improve generation reliability

How Google AI Studio simplifies experimentation with powerful image models

What surprised me most was how small changes in phrasing—like specifying camera angle or lighting—dramatically improved the cinematic quality of the generated characters.

Overall, this track helped me move from “just generating images” to building a real, usable AI-powered application.

prompt:

Create a highly detailed, original game character concept.
Character Type: {character_type}
Game Genre: {game_genre}
Art Style: {art_style}
Appearance:
Gender: {gender}
Age: {age_range}
Body Type: {body_type}
Height: {height}
Skin Tone: {skin_tone}
Facial Structure: {face_shape}
Eye Color & Style: {eye_details}
Hair Style & Color: {hair_details}
Scars / Tattoos / Marks: {special_marks}
Clothing & Armor:
Outfit Style: {outfit_style}
Armor Type: {armor_type}
Material: {materials}
Color Palette: {color_palette}
Accessories: {accessories}
Footwear: {footwear}
Weapons & Gear:
Primary Weapon: {primary_weapon}
Secondary Weapon: {secondary_weapon}
Magic / Tech Device: {device}
Backpack / Utility Gear: {utility}
Abilities & Theme:
Power Type: {power_type}
Element (if any): {element}
Personality: {personality_traits}
Alignment: {alignment}
Backstory Mood: {story_mood}
Pose & Expression:
Pose: {pose}
Facial Expression: {expression}
Action State: {action_state}
Environment:
Background Setting: {environment}
Time of Day: {time_of_day}
Weather / Atmosphere: {atmosphere}
Rendering & Quality:
Camera Angle: {camera_angle}
Lighting Style: {lighting}
Detail Level: ultra-detailed, cinematic, 8K quality
Style Keywords: game-ready, concept art, character sheet quality
Constraints:
No copyrighted characters
Original design only
Clean anatomy
High visual clarity