materials

Materials

Materials are built with EEVEE & Cycles nodes. To see which nodes are supported, please have a look at the list of supported nodes.

Table of Content

• Displacement
• Blending
• Transparency
• Read depth/Depth Textures
• Material parameters
• Shader uniforms
  • Available uniforms

Displacement

Locate the Armory Render Path - Renderer - Displacement property:

• Off - No displacement performed
• Vertex - Mesh vertices are displaced
• Tessellation - Mesh is first tessellated for more detail and then displaced

With Tessellation selected, the level of tessellation can be set using the Mesh and Shadow property.

Note: Vertices are displaced in normals direction. Use smooth shading (Space - Shade Smooth) for meshes with displacement to prevent gabs.

Examples:

• https://github.com/armory3d/armory_examples/tree/master/material_displace

Blending

To enable additive blending for specific material, set Armory Render Path - Blending to On and check the Blending property in Material - Armory Props.

Examples:

• https://github.com/armory3d/armory_examples/tree/master/material_translucent
• https://github.com/armory3d/armory_examples/tree/master/particle_examples

Transparency

• Connect an alpha map to the Principled BSDF input of a material.
• Material properties: Armory Props: Uncheck Alpha Test.

Read Depth/Depth Textures

Some materials need to read the scene's depth (e.g. for soft particles, sea foam etc.), which can be achieved by enabling the Armory Props > Read Depth option. Materials with this option then get access to a texture storing the content of the depth buffer.

This feature is currently unavailable on the forward render path if the compositor is disabled (Render Properties > Armory Render Path > Compositor).

The feature can be globally toggled on or off for a selected render path in Armory Render Path > Renderer > Depth Texture. If this option is set to Auto, the feature will be enabled only when there are materials in the exported scene with Read Depth enabled.

While rendering a frame, all materials with the Read Depth option enabled will be rendered after all the other materials without that option enabled. In between the rendering of both of those material sets, the depth buffer is copied to a dedicated depth texture so that the following depth-reading materials can read from it while simultaneously writing their depth to the actual depth buffer. Note that because of this order, all materials with the Read Depth option enabled will not be visible on the depth texture.

If a depth texture is used, it can be accessed via the depthtex shader uniform. The depth is stored in the red channel (x value) and the values depend on the near/far values of the active camera.

Examples:

• https://github.com/armory3d/armory_examples/tree/master/material_depth_texture

Material parameters

RGB, Value and Image Texture material nodes can be controlled at run-time using script or logic nodes. To expose material node, enable Parameter property in Node Editor - Properties - Armory Material Node.

Examples:

• https://github.com/armory3d/armory_examples/tree/master/material_params

Animating a parameter:

Shader uniforms

It is possible to retrieve additional light and scene data via uniforms. There are two different ways of using them:

• Using material nodes:

  It is possible to access uniform values with the Shader Data node. To do this, set the input type to Uniform and select the variable type (only uniforms of those data types are currently supported in node shaders). Then, look at Available uniforms and write the name of the link (e.g. _pointPosition) for the uniform into the Variable Name field.

  Please note that there is no viewport preview for the Shader Data node!

  Example:
  

• Custom materials:

  To pass a uniform to the fragment shader, add an entry in the material definition (example) under "shader_datas" > "contexts" > "constants":

  {
      "link": "<linkName>",
      "name": "<uniformName>",
      "type": "<uniformType>"
  }

  Replace <linkName> with the name of the link (e.g. "_pointPosition") that can be found in Available uniforms and replace <uniformName> and <uniformType> according to your fragment shader.

Available uniforms

(The following tables are not yet complete, please look into Uniforms.hx for all available uniforms).

Camera:

Link name	Type	Description
_cameraPlane	vec2	x: camera near plane, y: camera far plane
_cameraPosition	vec3	World position of the active camera
_cameraLook	vec3	Normalized look vector of the active camera in world coordinates
_cameraUp	vec3	Normalized up vector of the active camera in world coordinates
_cameraRight	vec3	Normalized right vector of the active camera in world coordinates
_fieldOfView	float	Field of view of the active camera
_viewMatrix	mat4	View matrix of the active camera
_transposeViewMatrix	mat4	View matrix of the active camera with rows and columns 0-2 (3x3) transposed
_projectionMatrix	mat4	Projection matrix of the active camera
_inverseProjectionMatrix	mat4	Inverse of the projection matrix of the active camera
_viewProjectionMatrix	mat4	View matrix multiplied with the projection matrix of the active camera
_inverseViewProjectionMatrix	mat4	View matrix multiplied with the projection matrix of the active camera and inversed
_prevViewProjectionMatrix	mat4	_viewProjectionMatrix from the previous frame

Lights:

Link name	Type	Description
_lightDirection	vec3
_lightPosition	vec3
_pointPosition	vec3
_pointColor	vec3
_sunColor	vec3
_sunDirection	vec3
_spotDirection	vec3
_lightArea0 - _lightArea3	vec3

Objects:

Link name	Type	Description
_uid	int	The UID of the object
_objectInfoIndex	float	The UID of the object
_objectInfoMaterialIndex	float	The UID of the object's current material
_objectInfoRandom	float	Random value that was assigned to the object during it's creation
_skinBones	float[]	Dual Quaternion skinning buffer. Only available when arm_skin is defined.

World:

Link name	Type	Description
_backgroundCol	vec3	The background color of the current world. (0, 0, 0) if not set
_envmapStrength	float	The strength of the world background. 0 if the scene has no world
_hosekSunDirection	vec3	The direction of the sun. The z value is clamped below (and including) 0 for the night cycle. (0, 0, 0) if the scene has no world

Other:

Link name	Type	Description
_time	float	The elapsed time since the beginning of the game
_vec2x	vec2	Base vector for the x axis ((1.0, 0.0))
_vec2xInv	vec2	Base vector for the x axis divided by the current render target width
_vec2x2	vec2	Base vector for the x axis multiplied by 2 ((2.0, 0.0))
_vec2x2Inv	vec2	Base vector for the x axis multiplied by 2 and divided by the current render target width
_vec2y	vec2	Base vector for the y axis ((0.0, 1.0))
_vec2yInv	vec2	Base vector for the y axis divided by the current render target height
_vec2y2	vec2	Base vector for the y axis multiplied by 2 ((0.0, 2.0))
_vec2y2Inv	vec2	Base vector for the y axis multiplied by 2 and divided by the current render target height
_vec2y3	vec2	Base vector for the y axis multiplied by 3 ((0.0, 3.0))
_vec2y3Inv	vec2	Base vector for the y axis multiplied by 3 and divided by the current render target height
_windowSize	vec2	Window size (x, y) in pixels
_screenSize	vec2	Screen size (size of the renderpath's current render target) in pixels
_screenSizeInv	vec2	Inverse of _screenSize (1.0 / _screenSize)
_aspectRatioF	float	Aspect ratio of the current render target (width / height)
_aspectRatioWindowF	float	Aspect ratio of the game window (width / height)