Distant Horizons

Distant Horizons is a mod which enables far greater render distances through the use of LODs. Iris allows shaders to integrate with this mod, ensuring that the blend between the vanilla terrain and the DH terrain can be seamless.

Programs

Terrain

Terrain gets the program dh_terrain. This runs before normal terrain.

Water

Water gets the program dh_water. This runs before normal water.

Shadow

Shadow pass gets the program dh_shadow. This runs before shadow terrain and shadow water respectively. The shadow pass retains the normal textures and projection.

Attributes

The following attributes are supported in DH programs:

gl_Vertex gl_MultiTexCoord2 gl_Normal gl_Color dhMaterialId

The following built in uniforms are supported:

gl_ModelViewMatrix(Inverse, etc) gl_ProjectionMatrix(Inverse, etc) gl_NormalMatrix

Definitions/Properties

Enabling the DH shadow pass

The DH shadow pass is automatically enabled. It can be turned on or off with the shader property dhShadow.enabled.

Distant Horizons has no set shadow distance; all chunks will be rendered.

Checking for Distant Horizons

All programs and properties have the DISTANT_HORIZONS define set if DH is enabled.

Samplers

Depth textures

There are two depth textures attached to Distant Horizons;

dhDepthTex0 and dhDepthTex1. These behave identically to their non-DH counterparts, except they have different near/far planes (explained below) and only contain DH terrain/water.

Uniforms

dhNearPlane

Declaration

uniform float dhNearPlane;

This uniform specifies the near plane of DH’s projection. This does not apply to the shadow pass.

dhFarPlane

Declaration

uniform float dhFarPlane;

This uniform specifies the far plane of DH’s projection. This is not the render distance! Use dhRenderDistance for that.

dhRenderDistance

Declaration

uniform int dhRenderDistance;

This uniform specifies the render distance currently set in DH.

dhProjection and variants

Declaration

uniform mat4 dhProjection;
uniform mat4 dhProjectionInverse;
uniform mat4 dhPreviousProjection;

This is the projection matrix for the non-shadow pass of Distant Horizons. This includes a different near and far plane, see the uniforms above.

Block IDs

Normal block IDs (mc_Entity) are not supported.

Iris provides “mini-IDs” in the form of int dhMaterialId automatically declared.

All Mini-ID’s get their own definitions that can be used in any program.

DH_BLOCK_UNKNOWN // Any block not in this list that does not emit light
DH_BLOCK_LEAVES // All types of leaves, bamboo, or cactus
DH_BLOCK_STONE // Stone or ore
DH_BLOCK_WOOD // Any wooden item
DH_BLOCK_METAL // Any block that emits a metal or copper sound.
DH_BLOCK_DIRT // Dirt, grass, podzol, and coarse dirt.
DH_BLOCK_LAVA // Lava.
DH_BLOCK_DEEPSLATE // Deepslate, and all it's forms.
DH_BLOCK_SNOW // Snow.
DH_BLOCK_SAND // Sand and red sand.
DH_BLOCK_TERRACOTTA // Terracotta.
DH_BLOCK_NETHER_STONE // Blocks that have the "base_stone_nether" tag.
DH_BLOCK_WATER // Water...
DH_BLOCK_AIR // Air. This should never be accessible/used.
DH_BLOCK_ILLUMINATED // Any block not in this list that emits light