docs: add light-shadows and shader examples pages

docs/.vitepress/config.ts

@@ -73,6 +73,8 @@ export default defineConfig({
           { text: 'Load Textures', link: '/examples/load-textures' },
           { text: 'Load Models', link: '/examples/load-models' },
           { text: 'Load Text', link: '/examples/text-3d' },
+          { text: 'Lights Shadows', link: '/examples/lights-shadows' },
+          { text: 'Using Shaders', link: '/examples/shaders' },
         ],
       },
       {

docs/examples/lights-shadows.md

@@ -0,0 +1,119 @@
+# Light-shadows
+
+This guide will help you get started with simple light and shadows in TresJS.
+
+We will build a simple scene with a three meshes and a plane but only two will have shadows.
+<SandboxDemo url="https://play.tresjs.org/#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" />
+
+## Let's first setup our scene (optional)
+
+We import all the modules that we need, for confort we can use the orbit-controls from cientos,
+[check here to know how](/examples/orbit-controls).
+
+Let's put 4 objects in our scene, one will be the plane that receive shadows, two of them will cast shadow and the last one will not cast shadow at all.
+
+I'm going to use [MeshToonMaterial](https://threejs.org/docs/index.html?q=toon#api/en/materials/MeshToonMaterial). Simple because you could see the "soft shadow" easily.
+
+```vue
+<script setup lang="ts">
+import { TresCanvas } from '@tresjs/core'
+import { OrbitControls } from '@tresjs/cientos'
+</script>
+
+<template>
+  <TresCanvas
+    clear-color="#111"
+    window-size
+  >
+    <OrbitControls />
+    <TresPerspectiveCamera :position="[5, 5, 5]" />
+
+    <TresMesh
+      :position="[-2, 2, 0]"
+      :rotation="[0, Math.PI, 0]"
+    >
+      <TresConeGeometry :args="[1, 1.5, 3]" />
+      <TresMeshToonMaterial color="#82DBC5" />
+    </TresMesh>
+    <TresMesh
+      :position="[0, 0, 0]"
+    >
+      <TresBoxGeometry :args="[1.5, 1.5, 1.5]" />
+      <TresMeshToonMaterial color="#4F4F4F" />
+    </TresMesh>
+    <TresMesh
+      :position="[2, -2, 0]"
+    >
+      <TresSphereGeometry />
+      <TresMeshToonMaterial color="#FBB03B" />
+    </TresMesh>
+    <TresMesh
+      :position="[0, -3, 0]"
+      :rotation="[-Math.PI / 2, 0, 0]"
+    >
+      <TresPlaneGeometry :args="[10, 10, 10, 10]" />
+      <TresMeshBasicMaterial color="#f7f7f7" />
+    </TresMesh>
+  </TresCanvas>
+</template>
+```
+
+## Lights (explanation)
+
+As you know every instance in [ThreeJs](https://threejs.org/) is available in **TresJs** so is all the light types, we just need to add the `Tres` prefix to use it.
+
+But not all lights can cast shadows, this definition comes directly from ThreeJs and made sense, for example the purpose of an (ambientLight)[https://threejs.org/docs/index.html?q=ambient#api/en/lights/AmbientLight] is to iluminate everysingle side of your scene, so make no sense to cast shadows, at the contrary a (DirectionalLight)[https://threejs.org/docs/index.html?q=light#api/en/helpers/DirectionalLightHelper] who is similar to the sun can cast shadow.
+
+Check this table to know which os the basic lights can cast shadows
+
+// TABLE
+
+## Shadows (explanation)
+
+There are also many types of shadows, for example the "soft shadow" it's generated automatially when an object receive more light from one side, but in summary a "normal" shadows that get projected in another surface it needs and object to be casted and an object to be receive. As we see in our example the `Plane` is receiving a shadow but not casting it.
+
+Internally ThreeJS generate automatically a new mesh with a (ShadowMaterial)[https://threejs.org/docs/index.html?q=shado#api/en/materials/ShadowMaterial] and it get update in each frame.
+
+## Setting our lights and shadow
+
+We could divide this in three step
+
+**Number 1**: Set the shadows on the renderer
+
+```vue
+//...
+
+<template>
+  <TresCanvas
+    clear-color="#111"
+    shadows
+    window-size
+  />
+  //...
+</template>
+```
+**Number 2**: Set the light to cast shadow
+
+We can simple put the boolean `cast-shadow` and in vue if you add to your object, Vue understand this as a `prop` with `true` value
+
+_The AmbientLight doesn't generate any type of shadow here_
+
+```vue
+//...
+
+<template>
+  <TresAmbientLight :intensity="1" />
+  <TresDirectionalLight
+    cast-shadow
+    :position="[0, 2, 0]"
+    :intensity="1"
+  />
+  
+  //...
+</template>
+```
+**Number 3**: Set the objects to cast shadow or receive shadows
+
+Similar to the previus step, 
+
+:::

docs/examples/shaders.md

@@ -0,0 +1,172 @@
+# Shaders
+
+This guide will help you get started with shaders in TresJS.
+
+We will build a simple scene with a blob. We will then animate the blob to softly distorted it.
+
+_Basic knowledge of how shaders work is necessary_
+
+<SandboxDemo url="https://play.tresjs.org/#eNqVVltv2zYU/iuE91BntSU7cYrBS4q0QTt0WNcgyfZSFxsjH9tMJVIjKdle4P++j9TFVJMU3oMDndvH71x4mIferSbzJs+jsqDetHdmEi1yywzZImcpl8vzWc+aWe/1TIosV9qyB2ZWPE3V+poWbMcWWmXsBaJf/By4ONRLLktuBqwwdE1yTvo3pfI24sLC5d7EidLd0E/6TthLJa1WqXnsLkhaZToRf1JilT5ufe1KE72YyZlMlDSW3aXqzpE9D5j3ZZGmR0BpnAopFkpnBl4PM8lYcSsymgK95GmBjxHbDbz+TZanwhbz0Chp3bDoj6LxgOHPURPwXtM/Bclk+0zA8WjATivv3Z5PSdrS5mbFUThw+nsma4awJMcBDeTQtbTnBZZFqjhydDn5nEuut0Iuq4jyj7JSKjFnGReyf1TVgDn7hGVqTumVMsIKJcHFyx+51WLDfvQu/by2Dtg4GrmyuuBOXLRlL9EAgHfVDmJPGeKwonnk9G2S0eZJzI3DTJT5BnPbxdw+g+kKFKRZCloHWTqxTbKDX1NZpn8F7rlW92gohH1lAsA6BqWGb+HqjV6jqU27F5ovM4x22PBcUyKMg89oLoosr9qI2EPbB4rvAXypUuUwfavQoIGLibZuTE/bjlV8KjYPTMn6toJteH/71Z2pzP3+A0NdLB8wSnluaM52R+z8dX28WLB+ffciP/ctr442yrglLXgaNXcw8t2qrCBQY7tQkNw5BmdxtaiwliBYQk8BAomxs/3uYUlKXA8Tlz722A/j8XjWc0tgrtaG8TRfcbYWEtLQiH+rcAB0N1DcqB3uFWmTuzaXdMkz0pxNm9HHAZ/HuPrV7wsOmi5UCe3k1H1zHwfRUZhK8MI31oT388J4NBpB6pz3kcyKaVrAXNfM+YdHopkTNBLn1XF15E2+Ik2/kMrI6i3O10vj/I8H7MT/HMPmrCbGDx/m17eDTcMdhNhQ9LQ7MwuHrsK5NB2FsfkMU4ybHH0fu1lPtbK8yXIIUqvo6gOLGcgj58cJX+G1eiLfMZz3vyeSdoe95UYkbd7tvEwmk+fYNmI1aFCcxcEU9ga96nUaZjyP7o2SeFv97M9qA8qA56ACnvXCx9AZZr2VtbmZxnEyl4jHJROljiTZWOZZHLpfnESn0SieC2Njp4b3rOcfng5w9Wz+H+wqAvCvQvha3T3Frol/zVH+A/Bb34tJhPGvkRtllAkXE2K7x/wQXOd3AcTTn8D3JZksLAP+P8EaO7i+gfvFGEsSiFgTtImybnVrP2wUjf10OHAV8D1oOA7nlIkDQBtXl/wkehWn4i6EbNYmZtIarPeFWH4zkYnKcpGS/pS769adTP//0q9eZ3VBLb9kRcnXJ/T3ZlNRvsKwkC5R7n0rcSfJVuZ3N7/TBt+tES9skdbNecZ4TUalheNYub0t5By0Az/P9oO/YHgeb827jSXpXtDHRO02J6/93GyDdtYqxRdfOO/v23H5nSrtMzuJTtqC7/4DVvHLxg==" />
+
+## Let's first setup our scene (optional)
+
+We import all the modules that we need, for confort we can use the orbit-controls from cientos,
+[check here to know how](/examples/orbit-controls).
+
+Also let's put our camera in the `[11,11,11]` position.
+
+Lastly just for help us with the location, let's add a simple plane, rotate in the X axis, with `[10, 10]` units in the geometry.
+
+```vue
+<script setup lang="ts">
+import { TresCanvas } from '@tresjs/core'
+import { OrbitControls } from '@tresjs/cientos'
+</script>
+
+<template>
+  <TresCanvas
+    clear-color="#111"
+    window-size
+  >
+    <OrbitControls />
+    <TresPerspectiveCamera :position="[11, 11, 11]" />
+
+    <TresMesh :rotation="[-Math.PI / 2, 0, 0]">
+      <TresPlaneGeometry :args="[10, 10]" />
+      <TresMeshBasicMaterial color="#444" />
+    </TresMesh>
+  </TresCanvas>
+</template>
+```
+
+## ShaderMaterial
+
+As you know every instance in [ThreeJs](https://threejs.org/) is available in **TresJs** so is the `ShaderMaterial`, we just need to add the `Tres` prefix to use it.
+
+For our blob, we could use a simple `SphereGeometry` adding some widthSegments and heightSegments to create a smooth effect. Also let's put our blob 4 units in the Y positive axis
+
+```vue
+    <TresMesh :position="[0, 4, 0]">
+      <TresSphereGeometry :args="[2, 32, 32]" />
+      <TresShaderMaterial />
+    </TresMesh>
+```
+
+The `ShaderMaterial` accept special properties like `uniforms` `vertexShader` and `fragmentShader`, so we can create it in our script section and make the bound with our instance.
+
+For this example our uniforms end like this:
+
+```ts
+import { Vector2 } from 'three'
+
+//...
+const uniforms = {
+  uTime: { value: 0 },
+  uAmplitude: { value: new Vector2(0.1, 0.1) },
+  uFrequency: { value: new Vector2(20, 5) },
+}
+//..
+```
+
+Our fragment shader, like this:
+
+```ts
+//...
+const fragmentShader = `
+precision mediump float;
+varying vec2 vUv;
+
+void main() {
+    gl_FragColor = vec4(1.0, vUv.y, 0.5, 1.0);
+}
+`
+//..
+```
+
+And lastly our vertexShader:
+
+```ts
+const vertexShader = `
+uniform vec2 uAmplitude;
+uniform vec2 uFrequency;
+uniform float uTime;
+
+varying vec2 vUv;
+
+void main() {
+    vec4 modelPosition = modelMatrix * vec4(position, 1.0);
+    modelPosition.y += sin(modelPosition.x * uFrequency.x - uTime) * uAmplitude.x;
+    modelPosition.x += cos(modelPosition.y * uFrequency.y - uTime) * uAmplitude.y;
+
+    vec4 viewPosition = viewMatrix * modelPosition;
+    gl_Position = projectionMatrix * viewPosition;
+    vUv = uv;
+}
+`
+//..
+```
+
+## Animating the blob
+
+Similar to what we learn in the [Basic animations](/examples/basic-animations) example.
+
+We start by referencing our blob, using [Template Ref](https://vuejs.org/guide/essentials/template-refs.html)
+
+```vue
+<script setup lang="ts">
+import { shallowRef } from 'vue'
+import { TresCanvas } from '@tresjs/core'
+import { OrbitControls } from '@tresjs/cientos'
+
+const blobRef = shallowRef(null)
+//...
+</script>
+
+<template>
+  <TresCanvas
+    clear-color="#111"
+    window-size
+  >
+    <OrbitControls />
+    <TresPerspectiveCamera :position="[11, 11, 11]" />
+    <TresMesh
+      ref="blobRef"
+      :position="[0, 4, 0]"
+    >
+      <TresSphereGeometry :args="[2, 32, 32]" />
+      <TresShaderMaterial />
+    </TresMesh>
+  </TresCanvas>
+</template>
+```
+ Once we got that we could use the `onLoop` callback to animate our `uTime`
+
+ ```ts
+import { TresCanvas, useRenderLoop } from '@tresjs/core'
+ 
+ //...
+ const { onLoop } = useRenderLoop()
+ 
+onLoop(({ elapsed }) => {
+   if (blobRef.value) {
+     blobRef.value.material.uniforms.uTime.value = elapsed
+   }
+})
+ //...
+```
+
+And that it is, we have our basic shader running smoothly
+
+## Using GLSL vite-pluging (optional)
+
+_This step is completly optional and is out of the scope of the **TresJs** team_
+
+Defining our shader inline, is not always the best idea, but if you're using VITE you can put your `GLSL` files in a different file just by using the (vite-plugin-glsl)[https://www.npmjs.com/package/vite-plugin-glsl].
+
+you could have a struncture similar to this:
+
+├── src/
+│   ├── myTresJsComponent.vue
+│   ├── shaders/
+│       ├── vertexShader.glsl
+│       ├── fragmentShader.glsl