AI HDRI Generator — HDR Environment Maps for Games & 3D

Last updated 2026-07-08

Atmos Forge creates HDRI environment maps for image-based lighting: import an HDR panorama, decorate it with float-preserving procedural tools — suns, planets, star fields, volumetric clouds, god rays — that keep true above-1.0 brightness, and export a .hdr file that Unity, Unreal Engine, and Blender import natively.

HDR pipeline is float-preserving end to end: decode → float compose → re-encode .hdr, never clamped to 0–1.
Volumetric clouds and mist use a physically based single-scattering ray marcher — sun-forward scattering exceeds 1.0 for correct IBL.
HDR uploads and exports up to 4096×2048; export format is .hdr (Radiance RGBE), which Unity and Unreal import directly.
HDR procedural composition is free — HDR compose operations are not metered.

What is an HDRI environment map?

An HDRI (high dynamic range image) environment map is a 360° panorama that stores real light intensities instead of display colors — a sun can be thousands of times brighter than the sky around it. Engines and renderers use HDRIs for image-based lighting (IBL): the image itself lights the scene, producing realistic reflections, ambient color, and sun highlights.

How does Atmos Forge handle HDR differently?

Most image tools clamp HDR data to screen range the moment you edit it, destroying the light information. Atmos Forge's HDR workflow keeps everything in floating point: every operation — adding a sun, compositing a planet, ray-marching volumetric clouds — reads and writes true float radiance. The exported .hdr keeps physically meaningful intensity, so your bright sun actually lights the scene.

What can I add to an HDRI?

Realistic suns with limb darkening, aureole glow, and air-mass reddening near the horizon
Procedural planets and moons with phase control and rings
Star fields with uniform density across the sphere
Volumetric clouds and mist (single-scattering ray-marched, HDR-only)
Emissive decorations: auroras, god rays, halos, arches, milky way bands
Seam fixing that preserves float values

Which tools import the exported .hdr?

Unity and Unreal Engine import .hdr natively — no conversion step. Blender loads .hdr as a world environment texture for lighting and background. Three.js loads it with RGBELoader. Atmos Forge deliberately ships .hdr rather than EXR because every major engine accepts it directly.

Frequently asked questions

Can Atmos Forge create HDRI environment maps?

Yes. Import an HDR panorama up to 4096×2048, decorate it with float-preserving procedural tools, and export a .hdr file for image-based lighting in Unity, Unreal Engine, Blender, and Three.js.

What format are HDRIs exported in?

.hdr (Radiance RGBE). Unity and Unreal Engine import it natively, and Blender and Three.js load it directly — no EXR conversion needed.

What is image-based lighting?

Image-based lighting (IBL) uses an HDR panorama as the light source for a 3D scene: the sky's real intensities drive reflections, ambient light, and sun highlights, producing far more realistic lighting than manual light rigs alone.

Do HDR edits cost credits?

No. HDR procedural composition in Atmos Forge is CPU-based and free — it is not metered like AI generation.

Why do volumetric clouds need HDR?

Forward-scattered sunlight through a cloud is brighter than 1.0 in display terms. An LDR image would clamp it; the HDR pipeline keeps the true intensity so the clouds light the scene correctly under IBL.

About Atmos Forge

Atmos Forge is a web-based AI skybox generator for creating seamless 360° equirectangular skyboxes, cubemaps, and HDRI environment maps for game engines and 3D workflows. It combines AI text-to-skybox generation with procedural sky composition tools — seam fixing, suns, moons, planets, star fields, and sprite compositing — and exports game-engine-ready files for Unity, Unreal Engine, Godot, Blender, Three.js, Babylon.js, and WebGL. Atmos Forge is made by Big Monk Games.

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