Ymir review
A free, graph-driven terrain generator with erosion, sculpting, seeds, and heightmap exports.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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.
Ymir pros and cons
- 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
Ymir fact sheet, pricing and score →
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