Ymir
Ymir: A free, graph-driven terrain generator with erosion, sculpting, seeds, and heightmap exports. Ranked #12 of 27 in Game Map Generators by our editors (8.2/10); pricing: Free plan; best for open-source terrain graphs and exports.
At a glance
- Editor score8.2 / 10
- PricingFree plan
- Best forOpen-source terrain graphs and exports
- Free planYes
- Paid fromFree
- Generation methodProcedural
- Facts checked20 Sep 2026
Where it wins
- Node graphs combine generators, modifiers, filters, erosion, and sculpting
- Thermal, hydraulic, and stream erosion support detailed terrain shaping
- Exports PNG, R16, and OpenEXR heightmaps with reproducible project seeds
Where it doesn't
- Project save format is not yet stable
- Desktop support is limited to Windows and Linux
- Workflow centers on terrain and heightmap generation rather than complete game scenes
Our verdict on Ymir
Ymir is a free, open-source desktop application for game developers and digital-content creators who need procedural terrain generation. Its node-based graph editor combines noise and shape generators with selectors, modifiers, filters, erosion models, painting, and sculpting tools. The workflow spans a 2D map view and a 3D terrain viewport, while heightmap import supports existing terrain sources. Ymir is available for Windows and Linux under the GPL-3.0 license, making it a fit for creators who value editable terrain graphs, reproducible generation, and an open distribution model.
The strongest part of Ymir is the breadth of its terrain-building workflow. Thermal, hydraulic, and stream erosion systems provide multiple ways to shape generated landscapes, while reusable subgraphs can organize repeatable graph sections. Project seeds support reproducible results, and headless command-line rendering suits automated generation workflows. The application exports heightmaps as 16-bit PNG, raw R16, or 32-bit OpenEXR files, with Unreal Engine listed as the engine export target. These capabilities make Ymir particularly suitable for technical artists and developers building terrain pipelines around heightmaps rather than complete game scenes.
Ymir is a strong choice for users seeking an open-source terrain graph editor without paid tiers, especially when Linux support, command-line rendering, or reproducible seeds matter. Its early 0.x development stage and unstable project save format call for care when building long-lived projects or shared production workflows. Users who need a mature project format, broader desktop coverage, or full scene authoring beyond terrain and heightmaps should consider a different tool. For procedural terrain exploration, erosion-driven shaping, and export-focused workflows, Ymir offers a focused and capable foundation.
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Ymir pricing
Ymir fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Generation method | Procedural |
| Map dimension | Both |
| Custom assets | Yes |
| Seed control | Yes |
| Engine export | Unreal Engine |
| Export formats | PNG, R16, OpenEXR |
| Deployment | Desktop |
| Platforms | Windows, Linux |
| Support | Community, Docs |
| Built for | Solo, Small business (editorial estimate) |
| Pricing | Free plan |
| Website | liminalfield.github.io |
| Facts checked | 20 Sep 2026 |
Alternatives to Ymir
- Heightmap Level GeneratorA free, open-source map generator with detailed terrain controls and engine-ready exports.9.4
- World MachineA mature procedural terrain tool with deep erosion, water, material, and export workflows.9.2
- Instant TerraA deep procedural terrain workflow for studios automating large environments.9.1
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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