Minor changes in ssao

examples/ssao-plugin/script.ts

     canvas: document.getElementById('mcanvas') as HTMLCanvasElement,
     msaa: true,
     plugins: [ProgressivePlugin],
+    tonemap: false,
 })
 
 async function init() {
 
     // to render ssao buffer to screen, uncomment this line:
     // viewer.renderManager.screenPass.overrideReadBuffer = ssaoTarget
+    // or set a custom pipeline
+    // viewer.renderManager.autoBuildPipeline = false
+    // viewer.renderManager.pipeline = ['gbuffer', 'ssao', 'screen']
 
     const targetPreview = await viewer.addPlugin(RenderTargetPreviewPlugin)
     targetPreview.addTarget(()=>ssaoTarget, 'ssao', false, true, true, (s)=>`${s} = vec4(${s}.r);`)

src/plugins/pipeline/SSAOPlugin.ts

     constructor(public readonly passId: IPassID, public target?: ValOrFunc<WebGLRenderTarget|undefined>) {
         super({
             defines: {
-                LINEAR_DEPTH: 1, // todo set from unpack extension
-                NUM_SAMPLES: 11,
-                NUM_SPIRAL_TURNS: 3,
-                PERSPECTIVE_CAMERA: 1, // set in PerspectiveCamera2
+                ['LINEAR_DEPTH']: 1, // todo set from unpack extension
+                ['NUM_SAMPLES']: 11,
+                ['NUM_SPIRAL_TURNS']: 3,
+                ['SSAO_PACKING']: 1, // 1 is (r: ssao, gba: depth), 2 is (rgb: ssao, a: 1), 3 is (rgba: packed_ssao), 4 is (rgb: packed_ssao, a: 1)
+                ['PERSPECTIVE_CAMERA']: 1, // set in PerspectiveCamera2
             },
             uniforms: {
                 tLastThis: {value: null},
         },
         shaderExtender: (shader, _material, _renderer) => {
             if (!shader.defines.SSAO_ENABLED) return
+            // todo: only SSAO_PACKING = 1 and 2 is supported. Not 3 and 4 right now.
             shader.fragmentShader = shaderReplaceString(shader.fragmentShader, '#include <aomap_fragment>', ssaoPatch)
         },
         onObjectRender: (_object, material, renderer: any) => {

src/plugins/pipeline/shaders/SSAOPlugin.pass.glsl

 
     float aoValue = sum * saoData.y * INV_NUM_SAMPLES;
 
-//    bool disableAO = getSelectionBit(getGBufferFlags(vUv).a) > 0 ? true : false;
+    //    bool disableAO = getSelectionBit(getGBufferFlags(vUv).a) > 0 ? true : false;
 
     aoValue = 1. - clamp(aoValue, 0., 1.);
 
+    // todo why so many packing options?
+    #if SSAO_PACKING == 1 // (r: ssao, gba: depth)
     // so that depth can also be sampled with ssao if required?
     gl_FragColor.gba = packFloatToRGB(centerDepth);
+    gl_FragColor.r = aoValue;// + (lastAO.r) * frameCount)/(frameCount+1.);
+    #elif SSAO_PACKING == 2 // (rgb: ssao, a: 1)
+    gl_FragColor.rgb = vec3(aoValue);
+    gl_FragColor.a = 1.;
+    #elif SSAO_PACKING == 3 // (rgba: packed_ssao)
+    gl_FragColor.rgba = packDepthToRGBA(aoValue); // from packing
+    #elif SSAO_PACKING == 4 // (rgb: packed_ssao, a: 1)
+    gl_FragColor.rgb = packFloatToRGB(aoValue);
+    gl_FragColor.a = 1.;
+    #endif
 
     //    vec4 lastAO = texture2D( tLastThis, vUv );
-
-//    gl_FragColor.r = (vec4(aoValue)).r;// + (lastAO.r) * frameCount)/(frameCount+1.);
-    gl_FragColor.r = aoValue;// + (lastAO.r) * frameCount)/(frameCount+1.);
+    //    gl_FragColor.r = (vec4(aoValue)).r;// + (lastAO.r) * frameCount)/(frameCount+1.);
+    //    gl_FragColor.r = aoValue + (lastAO.r) * frameCount)/(frameCount+1.);
     //    gl_FragColor.r = aoValue;
-
     //    gl_FragColor = vec4(centerDepth);
 }

src/plugins/pipeline/shaders/SSAOPlugin.patch.glsl

 
 #if defined(SSAO_ENABLED) && SSAO_ENABLED > 0
 
+// note: depth can also be sampled and used when SSAO_PACKING = 1.
+
 // reads channel R, compatible with a combined OcclusionRoughnessMetallic (RGB) texture
 float ambientOcclusion = tSSAOMapTexelToLinear ( texture2D( tSSAOMap, viewToScreen(vViewPosition.xyz).xy )).r; //todo: check encoding for tSSAOMap