Page History

Image Modified

Sample Render using the custom Voronoi 3D Texture Node.

The following package contains all the material described in this tutorial: Custom_Hypershade_Nodes.zip.

Section

Column

Shader development in 3Delight for Maya is quite simple. With OSL shaders, the process gets simpler yet, as 3Delight for Maya can automatically register as Maya shading nodes user-provided OSL shaders. 3Delight supports all the required functions to properly run OSL shaders including all the most advanced closures, refer to Performance Analysis for more informations.

This tutorial explains how to create your own HyperShade node. Shader development in 3Delight for Maya is very easy:

You don't need to install a compiler or any compilation tool.

Every created shader or texture is cross platform compatible

.

As examplesan example, we explain show how to develop a simple voronoi noise as a Maya 3D Texture and a simple Lambert shader pattern as a Maya 2D Texture. For more informations about procedural textures we recommend this modern classic: Texture & Modeling: a procedural apprach.

Column

width	35%

Panel

borderColor	#e0e0e0
bgColor	#f0f0f0
titleColor	#444444
title	Content:

Table of Contents

Main Components

maxLevel	2

Using the example package

Download and decompress Custom_Hypershade_Nodes.zip. To use the package files, you can either copy them to specific locations of your 3Delight installation, or define environment variables to indicate their locations.

Copying example files to your 3Delight installation

Copy the customShadingNodes directory itself into the maya folder of your 3Delight installation - for instance, place the directory copy into C:\Program Files\3Delight\maya\ on a default Windows installation of 3Delight Studio Pro, so to have it in C:\Program Files\3Delight\maya\customShadingNodes
Optional - copy the files from the icons directory into the icons folder of your 3Delight installation. Make sure to choose the subdirectory that corresponds to the Maya version you are using. For instance, on a default Windows installation of 3Delight Studio Pro, for Maya 2015, the correct destination location is C:\Program Files\3Delight\maya\2015\icons.

Or, defining environment variables

The XBMLANGPATH definition is optional. On Linux, paths set in XBMLANGPATH must end with /%B .

Environment Variable	Value
`_3DFM_USER_OSL_PATH`	Path to the `customShadingNodes` directory of the downloaded package.
`XBMLANGPATH`	Path to the `icons` directory of the downloaded package.

Lauch Maya and go to the Hypershade editor. The OSLVoronoi node should appear listed under 3Delight → Texture in the Create tab, and under 3Delight OSL Texture in the Create menu. Note that the Maya script editor will report the creation of the new OSL nodes.

Image Added

The Voronoi node viewed in the Create menu of the HyperShade

Image AddedThe Voronoi node viewed in the Node Editor. The place2dTexture node is automatically created and connected.

Image AddedVoronoi noise connected to the 3Delight Material.

Components of a custom shading node

There is only one required component to define a custom shading node: a compiled OSL shaderTo create a single node only OSL shader is needed. Optionally, it is possible to add icons to have a better visual representation of the node inside Hyerpshade inside the Hypershade and the Outliner.

Components location

The following table shows where each component should be installed for a Maya 2015 packagethe default location where 3Delight for Maya will look for components, and the environment variable that allows you to specify another location for them.

Component

Installation

Environment Variable	Default Location
Compiled OSL

shader path

shaders _3DFM_USER_OSL_PATH

`C:\Program Files\3Delight\maya\customShadingNodes`
Icons	`XBMLANGPATH`	`C:\Program Files\3Delight\maya\2015\icons`

Creating a Custom 3D Texture Node

After correctly providing the compiled OSL shader path, you will be able to render using the new texture as with any other Maya 3D Texture.

Image RemovedThe Voronoi node viewed in the Node Editor. Note how place3dTexture node is automatically supported.

Image RemovedVoronoi noise connected to the 3Delight Material.

The OSL Source Code

The Voronoi texture looks like a standard Open Shading Language function but with some optional metadata:

The source code for our voronoi texture follows

(varies according to the Maya version being used)

The compiled shader

This is a standard Open Shading Language surface shader, complied with oslc (provided with the 3Delight Studio Pro package). The shader source code can be annotated to provide indications to 3Delight for Maya about the Maya shading node classification and its appearance in the Attribute Editor.

Warning

While annotations are optional, it is highly recommended to provide the shader annotation that specifies the type ID.

Expand

title	More info...

When no type ID is provided as annotation, 3Delight for Maya will attempt to generate one in the range reserved for studio internal node types Because this range is not large enough, it is possible that two different OSL shader names will result in identical type IDs; this will cause problems when reading a scene in Maya Binary format. For this reason, using the automatically generated IDs is not recommended for usage outside of prototyping purposes, refer to mayaid.autodesk.io to obtain a reserved block of IDs.

Expand the annotations section below and refer to the maya_typeID shader annotation for more details on how to define your type ID.

Expand

title	More details about the OSL annotations...

Annotations in the OSL source code

The annotations are defined between double square brackets. Multiple, comma-separated annotations, can be used in one set of double square brackets.

Shader annotation

This annotation is provided between the shader name and its parameter list. For instance:

surface OSLVoronoi [[ string maya_type = "texture", string maya_typeID = "0x00" ]] ( ... )

The supported shader annotations are:

string maya_typeID

Specifies the type ID used for the node registration. This is a integer that Maya uses to identify the node type, most notably when saving a scene in the Maya Binary format. Each OSL shader that defines a given shading node type should be assigned a unique type ID. You can chose a value between 0x0000 and 0x007F, or between 0x7F01 and 0x7FFF for your shading node type.

The IDs from 0x0000 to 0x7FFF are reserved for node types that are used internally in a studio. 3Delight for Maya will generate a type ID between 0x0080 and 0x7F00 if no maya_typeID annotation is provided. You can also request your own reserved node ID range to Autodesk, for free. This is also the recommended solution if you intend to share your nodes with users outside your studio.

You may use any ID between 0x0000 and 0x7FFF if you always provide the maya_typeID annotation for every custom OSL shader you define. In this case 3Delight for Maya will never need to generate a type ID.

string maya_type

Specifies the Maya shading node classification. The classification affects where the node is presented in the Hypershade tree lister and menus. Some classification types will also change the node creation mechanism to automatically create and connect related nodes - for instance, creating a surface shader will also create and connect a shading group.

The currently supported types are:

texture

The shading node will be classified as a texture node. The node will be classified as a 2D texture node, for which Maya automatically create and connect a place2DTexture node, if:

- it contains a float[2] parameter that has the string maya_name = "uv" annotation, and
- it contains a float[2] parameter that has the string maya_name = "uvFilter" annotation.

lens

The shading node will be classified as a lens shader. Lens shaders can be connected to a camera's lens shader 3Delight extension attribute.

surface

The shading node will be classified as a surface shader. It will be connected to a shading group upon creation.

Parameter Annotations

Parameter annotations are provided between a parameter's default value and the comma that ends its declaration. For instance:

float i_jitter = 1.0 [[ string maya_name = "jitter" ]],

The supported parameter annotations are:

string maya_type

Specifies the type of the Maya attribute related to the shader parameter. For now, only bool is supported to display an integer parameter as a checkbox.

string maya_name

Specifies the name of the Maya attribute related to the shader parameter.

string maya_label

Specifies the label to use for the Maya attribute in the various Maya editors (Attribute Editor, Node Editor, Channel Box, etc.).

string maya_group

Specifies the label of a Frame Layout into which the Maya attribute will be displayed in the Attribute Editor.

float maya_min

Specifies the soft minimum value for the Maya attribute attribute related to the shader parameter.

float maya_max

Specifies the soft maximum value for the Maya attribute attribute related to the shader parameter.

int maya_hidden

When set to 1, the Maya attribute will not be shown in the Attribute Editor. It will still be visible in the other Maya editors (Node Editor, Channel Box, etc.).

Annotated OSL shader example

#include "texture3d.h" #include "utils.h" surface OSLVoronoi

Expand

title	Show OSL code...

Code Block

language	cpp
theme	Eclipse
title	OSL Shader Source (OSLVoronoi.osl)

collapse true

/** Returns the U comp of the default UV set */
float GetS()
{
	float st[2];
	if( getattribute("st", st) )
	{
		return st[0];
	}
	else
	{
		return u;
	}
}

/** Returns the T comp of the default UV set */
float GetT()
{
	float st[2];
	if( getattribute("st", st) )
	{
		return st[1];
	}
	else
	{
		return v;
	}
}


surface OSLVoronoi [[ string maya_type = "texture" ]] (
		float i_jitter = 1.0 [[
			string maya_name = "jitter",
			string maya_label = "Jitter",
			float maya_min = 0.0,
			float maya_max = 1.0,
			string maya_group = "3Delight Voronoi" ]],
		float i_

scale

seed = 1.0

.1

 [[
			string maya_name = "

scale

seed",
			string maya_label = "

Scale

Seed",
			float maya_min = 0.0,
			float maya_max = 2.0,
			string maya_group = "3Delight Voronoi" ]],
		float i_

seed

uvCoord[2] =

1.0

{GetS(), GetT()} [[
			string maya_name = "

seed

uv",

string

int maya_

label

hidden =

"Seed"

1,

string

int

maya

skip_

group

init =

"3Delight

Voronoi"

]],
		float i_

uvCoord

uvFilterSize[2] = {

GetS() / i_scale

0,

GetT() / i_scale}

0} [[

[[

string maya_name = "

uvCoord

uvFilterSize",
			int maya_hidden = 1,
			int skip_init = 1 ]],

		output color outColor = 0.0 [[
			int maya_hidden = 1 ]],
		output float outDistance = 0.0 [[
			int maya_hidden = 1 ]] )
{
	float edgeDist;
	float outside;

	/* 
		i_uvCoord is multiplied by 10 to produce a visible result with default 
		place2DTexture. This is similar to setting RepeatU / V to 10.
	*/
	point pp = point(i_uvCoord[0] * 10, i_uvCoord[1] * 10, i_seed);

	point position;

	point thiscell = point( floor(pp[0])+.5, floor(pp[1])+.5, floor(pp[2])+.5);
	float f1 = 1000;
	for (int i = -1;  i <= 1;  i += 1)
	{
		for (int j = -1;  j <= 1;  j += 1)
		{
			for (int k = -1;  k <= 1;  k += 1)
			{
				point testcell = thiscell + vector(i,j,k);
				point pos =


					testcell + i_jitter * ((vector)cellnoise(testcell) - 0.5);
				vector offset = pos - pp;
				float dist = dot(offset, offset); /* actually dist^2 */
				if (dist < f1)
				{
					f1 = dist;
					position = pos;
				}
			}
		}
	}

	outDistance = sqrt(1 - f1);
	outColor = outDistance;
}

Adding Icons for the Outliner and Hypershade

Anchor
icons
icons
The icons

You can add icons to both the Outliner and Hypershade (this applies to both texture nodes and shader nodes). The table below details the convention for creating the icons for our Voronoi Noise.

	Outliner

Image Removed

Image Added	HyperShade - Node Lister

Image Removed

Image Added	HyperShade - Work Area

Image Removed

Image Added
Icon Resolution	20 x 20 pixels	32 x 32 pixels	128 x 128 pixels (up to 512 x 512 pixels)
Format	Transparent 24 bits PNG	Transparent 24 bits PNG	Transparent 24 bits PNG
Naming Convention	"out_" + <node_type> + ".png"	"render_" + <node_type> + ".png"	<node_type> + ".png"
Example	out_3DelightVoronoi.png Image Modified	render_3DelightVoronoi.png Image Modified Note the transparent corners of the icon matching Maya built-in

3D Textures

2D Texture nodes.

render_3DelightVoronoi.png

Image Modified

Page tree

Versions Compared

Old Version 4

New Version Current

Key

Main Components

Using the example package

Copying example files to your 3Delight installation

Or, defining environment variables

Components of a custom shading node

Components location

Creating a Custom 3D Texture Node

The OSL Source Code

The compiled shader

Annotations in the OSL source code

Shader annotation

Parameter Annotations

Annotated OSL shader example

Anchor
icons
icons
The icons

Page tree

Page History

Versions Compared

Old Version 4

New Version Current

Key

Main Components

Using the example package

Copying example files to your 3Delight installation

Or, defining environment variables

Components of a custom shading node

Components location

Creating a Custom 3D Texture Node

The OSL Source Code

The compiled shader

Annotations in the OSL source code

Shader annotation

Parameter Annotations

Annotated OSL shader example

AnchoriconsiconsThe icons

Anchor
icons
icons
The icons