NodeMaterial revision

[sunag]

This includes fixes and example of @DanielSturk, irradiance feature and better interface for Color Space using nodes.

Related:
#16788
#16668
#16375

Changes

• unify Math1Node, Math2Node, Math3Node to MathNode
• new ColorSpaceNode
• new example webgl_materials_envmaps_hdr_nodes.html
• rename Node.parse to Node.analyze
• rename Node.buildCode to Node.flow
• rename Node.eval to Node.parse
• move NodeBuilder.optimize = false to NodeBuilder.context.ignoreCache = true
• fix irradiance LDR, HDR and RGBM16
• fix RectAreaLight

https://rawgit.com/sunag/three.js/dev-fix-TextureCubeNode/examples/index.html?q=nodes#webgl_materials_envmaps_hdr_nodes

[sunag]

How should we call the vector2?
This is the indirect(irradiance) cube coords vector.
/ping @WestLangley @bhouston @mrdoob

Select vector2 in scope option:
https://rawgit.com/sunag/three.js/dev-fix-TextureCubeNode/examples/webgl_materials_nodes.html?e=node-reflect

[sunag]

Here the original code:

three.js/src/renderers/shaders/ShaderChunk/envmap_physical_pars_fragment.glsl.js

Line 30 in 2ad018c

vec3 queryVec = vec3( flipEnvMap * worldNormal.x, worldNormal.yz );

[sunag]

Opts it is a world normal with flipEnvMap!?

new THREE.NormalNode( THREE.NormalNode.WORLD )

[DanielSturk]

Great progress! Looking forward to seeing these changes made

[sunag]

Thanks @DanielSturk!

Done the fixes and update the example. The visual result should be the same for both nowMeshStandardNodeMaterial and MeshStandardMaterial.

https://rawgit.com/sunag/three.js/dev-fix-TextureCubeNode/examples/webgl_materials_envmaps_hdr_nodes.html

[sunag]

@donmccurdy following your tip.
4665931

[donmccurdy]

Where does onBeforeCompile.toString get called?

[sunag]

It is used to create a hash modification in onBeforeCompile. More details:
#14442
#16668

[sunag]

#15674

[donmccurdy]

I don't see anything calling toString() in these PRs?

[sunag]

In 15674 have a commit calling toString
07236bb
The description of the problem:
#15674 (comment)

I think that this approach will be improved in the future...

three.js/src/renderers/webgl/WebGLPrograms.js

Line 249 in 7fe9a41

array.push( material.onBeforeCompile.toString() );

[donmccurdy]

@sunag thank you! :)

---

In words, how would you define 'analyze', 'parse', and 'flow' as they relate to NodeMaterial? I'm having some trouble understanding what "analyze" means — the word usually doesn't imply side effects, but in this case analyze() calls methods like build() and addFlow().

[sunag]

Primary process

1. analyze() It is necessary to analyze and validate all nodes and slots(channels), it is will generate info necessary for build the code, share nodes(create temp vars), optimization as well the variable type and the return value.

2. flow() It generates codes, includes functions, defines, uniforms, expressions, and other codes need to work the shader. It depends on analyze be execute before flow to generate info necessary to build the code/shader. flow returns all data (code and extras values) of the slot/channel.

3. analyzeAndFlow() Call the two methods analyze and after the flow. It does not optimize the shader if used many slots/channels, for the reason, it is mostly used in position slot of the vertex shader.

Secundary process

4. build returns the final value(expression), generate by generate function or the variable generated by NodeTemp just like any other optimization node.

5. generate create the snippets fundamental to generate the shader. Here too, is responsible to include functions, defines, etc returned in flow. generate return only the final expression converted to output or parent node using format function.

The process superficially is similar to this diagram:

[sunag]

parse is used only to parse GLSL code, example is FunctionNode and StructNode

[donmccurdy]

Thanks! I'm confused, but I appreciate the detailed writeup. Probably I need to read the code more and see what calls what. 😅

[mrdoob]

@donmccurdy should I merge this one for now or do you want to take a closer look?

[donmccurdy]

Good to merge. 👍

[mrdoob]

Thanks!