Monster Mash
Monster Mash turns a flat sketch into an animated 3D character entirely inside the browser. Draw the outline, inflate it into volume, then drag control pins to make it move. Free, no account, no 3D skills required.
What is Monster Mash?
Monster Mash is a sketch-based modelling and animation tool that runs entirely in a web browser. It compresses a job that normally demands a 3D package, a modeller and a rigger into three buttons: Draw, Inflate and Animate. Everything happens in the flat sketching plane, and no 3D manipulation is required at any point.
In Draw mode you outline your character one region at a time. A single stroke defines each region, and the order in which you create them sets their depth order. A closed stroke makes a main body part; an open stroke makes a part that attaches smoothly to another, with the tool closing the gap itself along a junction line, which is how limbs connect without any manual work. Clicking inside a region selects it and double-clicking duplicates it behind the others, so a pair of arms or eyes takes seconds. A separate Redraw option reshapes an existing region without disturbing its place in depth.
Inflate turns the flat drawing into a rounded 3D mesh you can rotate, pan and push around. Animate is where the tool earns its name: you drop control pins on the model, drag them, and record their motion. The first motion recorded defines the length of the animation cycle, its pin is marked in green, later pins start at the cycle position currently playing, and the plus and minus keys shift their timing against that master. Motion can be copied and pasted between pins.
Results leave through open formats. Projects save to your local drive, the current frame exports as a Wavefront .obj with material and texture, and the whole textured animation exports as glTF .glb, which imports into Blender with frames arriving as morph targets converted to shape keys. The animation is vertex-based rather than skeleton-based, which is worth knowing before you plan a pipeline around it.
The tool is the demo accompanying a SIGGRAPH Asia 2020 paper by Dvorozvnak and colleagues, published in ACM Transactions on Graphics, and it combines 3D inflation with a rigidity-preserving layered deformation model called ARAP-L. The source code sits on GitHub under Apache 2.0, and the demo itself is free to use for evaluation and research purposes.
What it does
- Turn a 2D sketch into a 3D mesh in one click, with no 3D manipulation
- Animate a model by placing control pins on it and dragging them around
- Record pin movements over time and play the result back as a synchronised loop
- Export a full textured animation to glTF (.glb) for Blender and other 3D software
- Export the current animation frame as a Wavefront .obj with its material and texture
- Texture a character from an imported template image traced in the sketching plane
- Build layers from a mask image, holes included, and reorder them in depth
When to use Monster Mash / When not to
A quick filter to help you decide if Monster Mash is the right fit.
When to use Monster Mash
- Illustrators and 2D animators who want to see their drawings move without building a rig
- Complete beginners in 3D, since every interaction happens in the flat sketching plane
- Storyboard artists and professional animators looking for a fast, throwaway space to test an idea
- Art teachers and their students, who get a free browser tool with nothing to install or sign up for
- Game developers and 3D artists needing quick placeholder characters exported as glTF or OBJ
When not to use Monster Mash
- Studios needing precision modelling, as the mesh comes from automatic inflation rather than controlled geometry
- Riggers and pipelines built on skeletons, since the exported animation is vertex-based morph targets
- Anyone working on a phone or a small screen, which the interface explicitly does not handle well
- Teams requiring a contract, a support desk or a data processing agreement, none of which exist here
- Developers wanting to automate the tool, as there is no API and no documented integration
How to use Monster Mash
A typical end-to-end flow, from setup to results.
- Open the site in a recent browser: there is nothing to install and no account to create
- Optionally import a template image to trace over, which will also become the texture of the final model
- In Draw mode, sketch the main body with a single closed stroke
- Add limbs and eyes with open strokes, which the tool attaches to the body automatically
- Double-click a region to duplicate it behind the others, for symmetrical parts
- Switch to Inflate to check the 3D volume, rotating and nudging parts until the shape reads well
- Switch to Animate and drop control pins on the parts you want to move
- Turn on recording, then drag a pin: the first motion you record sets the length of the animation cycle
- Record the remaining pins, shift their timing with the plus and minus keys, and preview with the space bar
- Save the project first, since the glTF export builds the file in memory and can crash on long animations, then export the frame as .obj or the animation as a .glb
Pros & Cons
Pros
- Free with no account, no sign-up and no installation: the address is the whole product
- Genuinely learnable in minutes, with a three-step quick start opening the help panel
- No 3D or rigging knowledge needed, which is the entire point of the single-view approach
- Runs on any operating system with a recent browser, and takes mouse, touch or stylus input
- Exports to open, standard formats, .obj and glTF .glb, that Blender reads directly
- Source code published on GitHub under Apache 2.0, so the tool can be inspected, built and modified
- Backed by a peer-reviewed SIGGRAPH Asia 2020 paper rather than by marketing claims
Cons
- No terms of service and no privacy policy for the tool itself; the only such documents cover the forum
- No contact email, no postal address and no company name published anywhere
- Development has effectively stalled, the last entry in the What's New log being dated 28 August 2022
- The interface is not optimised for small screens, so a tablet or a desktop is effectively required
- Needs WebAssembly and WebGL 1.0 plus sufficient computing power, and can crash on weaker devices
- The glTF export builds the file in memory and can crash the tool on a long animation
- Vertex-based output only, with no API, no mobile app and no integrations beyond file formats
Pricing & Plans
Monster Mash is offered free of charge in its entirety. There is no pricing page, no paid tier and no published amount in any currency, and the tool requires no account. The site frames this free access as being for evaluation and research purposes. The source code is likewise available at no cost, under the Apache License 2.0.
Data, GDPR & hosting
A consolidated view of how Monster Mash handles your data.
GDPR overview
There is no mention of the GDPR anywhere on Monster Mash or on its forum. Targeted searches across every page collected, in the rendered text and in the raw HTML alike, returned nothing for the GDPR, data subject rights, lawful basis, erasure or a data protection officer. No controller is identifiable either: the site publishes no company name, no postal address and no contact email, so there is nobody to address a request to. The closest thing to a statement sits in the forum's stock phpBB policy, which says account information is protected by the data-protection laws applicable in the country that hosts us, without ever naming that country. Treat the tool as carrying no documented GDPR position. In mitigation, it runs in the browser and asks for no personal data; only the optional forum account requires an email address.
Who owns the data?
Monster Mash publishes no terms of service and no privacy policy of its own, so no document states who owns what you make with it. In practice the question is largely moot: the tool runs inside your browser and projects are opened from and saved to your own hard drive, so your models never reach a server that could claim them. The only rules the operator publishes cover the separate user forum, and they are the stock phpBB texts. Whatever you type there is stored in a database, the IP address of every post is logged, and the operator undertakes not to disclose that information to third parties without your consent.
Reuse rights
Nothing on the site asks you to request permission before reusing what you produce, and there is no licence clause covering user creations at all. Everything you make leaves the tool through ordinary file exports that stay on your own machine: a project file, a template image for texturing, a Wavefront .obj of the current frame with its .mtl material and .png texture, or a glTF .glb of the whole textured animation. The one restriction the site does state concerns the demo itself rather than its output, which is offered free to use for evaluation and research purposes. The source code is a separate matter again: the src directory is published under the Apache License 2.0, while code in the third_party directory may carry more restrictive licences, and the Triangle library must be obtained separately under its own terms.
Data retention & training
Hosting summary
No hosting jurisdiction is declared. Monster Mash names no country or region where user data would be stored, and publishes no trust or security page. This matters less than it usually would, because the tool is a client: it executes in your browser through WebAssembly and WebGL, and projects are opened from and written to your own hard drive, so there is no documented upload of user content to host anywhere. The site itself is served behind Cloudflare, the resolved address 104.21.72.232 belonging to Cloudflare's anycast network, but that locates a content delivery node rather than any data store and should not be read as telling you where your own files would live. The domain is likewise registered through Cloudflare, a United States registrar. The only hosting statement the operator makes anywhere concerns the separate forum, whose stock policy says account information is protected by the data-protection laws applicable in the country that hosts us, without ever naming that country. For anything beyond casual use, treat the hosting position as undocumented.
Things to keep in mind
Risks and trade-offs to weigh before adopting Monster Mash.
- With no terms and no privacy policy for the tool, you have no stated recourse if something goes wrong
- The publisher cannot be identified, with no company name, no address and no email, so there is nobody to write to
- Your work exists only on your own machine: a browser crash or a lost file means the project is gone, as nothing is backed up for you
- The glTF export builds the file in memory and can crash the tool, taking unsaved work with it
- Its demo status, framed for evaluation and research, leaves commercial use uncovered by any document
- Little maintained since 2022 and dependent on WebGL 1.0, it could quietly stop working as browsers move on
- The ease of a good-looking result can stand in for learning volume, timing and rigging, which is a real risk for students treating it as a shortcut
Setup & Integrations
Technical difficulty
Essentially none for the end user. There is no installation, no account and no configuration: opening the address in a recent browser that supports WebAssembly and WebGL 1.0 is the entire setup. A device with reasonable computing power helps, and the site recommends a stylus on a tablet, warning that the interface suits larger screens. If it crashes, the advice given is to update your operating system and browser. Building the tool from source is a different matter and squarely for developers, requiring CMake, Emscripten or clang/gcc, and the separately obtained Triangle library.
Deployment
Integrations
Supported languages
Behind Monster Mash
Resources
All the official URLs gathered for verification and reference.
Frequently asked questions
How much does Monster Mash cost?
Do I need to install anything or sign up?
What do I need to run it?
Do I need to know 3D modelling?
Which formats can I export to?
Can I bring the animation into Blender?
Are my creations uploaded to a server?
How do I get help or send feedback?
Is the source code available?
Is the tool still being updated?
Should you pick Monster Mash?
Monster Mash is a rare thing: a research demo that became a genuinely usable tool and then simply stayed online. The promise is narrow and it is kept. You draw a creature, inflate it, pin it, and a few minutes later you have a looping 3D animation you can open in Blender, without ever having touched a 3D viewport or built a rig. For ideation, storyboarding, teaching and plain play, that is an excellent trade, and it costs nothing.
The price is paid elsewhere. There is no company behind the tool in any formal sense: no legal name, no address, no contact email, and no terms of service or privacy policy covering the tool itself. The only legal documents on the domain are the default forum texts. Nothing here looks hidden or sinister, and the fact that the tool runs in your browser and saves to your own disk is precisely why so little needs saying, but an organisation that requires a contract, a data processing agreement or a support commitment will find nothing to sign.
Its other limit is time. The last product change was logged in August 2022, and the output is vertex-based rather than skeletal, which makes it a poor starting point for a conventional animation pipeline. Treat what you export as a sketch, not as an asset to build a production on. Encouragingly, the forum was still receiving posts in August 2026, so the tool is neither abandoned by its users nor broken.
Use it for what it was designed to do: fast, casual, single-view character animation, free and in the browser. Judged on that, it is hard to fault. Judged as production software, it never claimed to be that.
- Choosing a selection results in a full page refresh.
- Opens in a new window.