Post a Comment On: C0DE517E

Yesterday I did a small test with stereo rendering, trying to reproject the image from one eye to the other. It's very crude but I wanted to show the "theory" or the basic idea of the procedure as I got a few people asking me about it.
[Image] Stereo rendering (standard red/cyan glasses needed)
Of course the most interesting thing is how to correctly inpaint the holes in your visibility. This is a very general problem that also applies to other post effects like motion blur and depth of field blur, the solution I use in this test well... I won't even call it a solution. 

Much better methods have to be used for this to work decently, but that will (might...) be the topic of another post!
[Image] Reconstructed view [Image] Rendered view



 float Script : STANDARDSGLOBAL <    string UIWidget = "none";    string ScriptClass = "scene";    string ScriptOrder = "standard";    string ScriptOutput = "color";    string Script = "Technique=Main;";> = 0.8; // version #// -- Untweakablesfloat4x4 WorldViewProj : WorldViewProjection < string UIWidget="None"; >;float4x4 WorldView : WorldView < string UIWidget="None"; >;float4x4 Proj : Projection ;float2 BufferSize : ViewportPixelSize < string UIWidget="None"; >;float4 ClearParam < string UIWidget="None"; > = {0,0,0,0};// -- Buffers and samplerstexture Bake : RENDERCOLORTARGET<    float2 ViewPortRatio = {1,1};    string Format = "A8B8G8R8";    string UIWidget = "None";>;sampler2D BakeSampler = sampler_state{    texture = ;    MagFilter = Point;    MinFilter = Point;    AddressU = Clamp;    AddressV = Clamp;    MipFilter = Point;};// -- Data structuresstruct GeomVS_Out{    float4 Pos : POSITION;    float4 PosCopy : TEXCOORD0;    float2 UV : TEXCOORD2;};struct FSQuadVS_InOut // fullscreen quad{    float4 Pos : POSITION;    float2 UV : TEXCOORD0;};// -- ShadersGeomVS_Out GeomVS(float4 pos : POSITION, float2 uv : TEXCOORD0){    GeomVS_Out Out;    Out.Pos = mul( pos, WorldViewProj );    Out.PosCopy = Out.Pos;    Out.UV = uv;        return Out;}FSQuadVS_InOut FSQuadVS(FSQuadVS_InOut In){        return In;}// FX Composer does not pass near and far planes via a semantic, we have to "extract" themfloat2 GetPlanesFromDxProjection(){    float near = -Proj[3][2] / Proj[2][2];    float far = -Proj[3][2] / (Proj[2][2] - 1.0);        return float2(near, far);}float4 EncUnitRangeToRGBA8( float v ){    float4 enc = float4(1.0, 255.0, 65025.0, 160581375.0) * v;        enc = frac(enc);    enc -= enc.yzww * float4(1.0/255.0, 1.0/255.0, 1.0/255.0, 0.0);        return enc;}float DecUnitRangeToRGBA8( float4 rgba ) {    return dot( rgba, float4(1.0, 1/255.0, 1/65025.0, 1/160581375.0) );}float4 BakePS(GeomVS_Out In) : COLOR{    // 0 to 1 from near to far    float linearDepth = In.PosCopy.z / GetPlanesFromDxProjection().y;        float testColor = dot(frac(In.UV.xy * 10) ,0.5.xx) + 0.25;        return float4(EncUnitRangeToRGBA8(linearDepth).xyz, testColor);}float4 DecodeBake(float2 uv){    float4 sample = tex2D(BakeSampler, uv);    float linearZ = DecUnitRangeToRGBA8(float4(sample.xyz,0));    // back to viewspace...    float2 nearFar = GetPlanesFromDxProjection();    linearZ = linearZ * (nearFar.y-nearFar.x) + nearFar.x;#define VIEWTOUVMULT (float2(Proj[0][0], -Proj[1][1]) * 0.5)#define VIEWTOUVADD float2(0.5, 0.5)        float2 xy = ((uv - VIEWTOUVADD) * linearZ)/VIEWTOUVMULT;        return float4(xy, linearZ, sample.w); // view xyz, pattern}float4 CopyPS(FSQuadVS_InOut In) : COLOR{    return float4(DecodeBake(In.UV).zzz / 5, 1);    return float4(DecodeBake(In.UV).www, 1);}float3 ReprojectView(float3 viewPos){    // Here we should go from the view position of the baked eye to the one of the other    // it can be pretty generic but it assumes the difference will be only along the    // screen X axis...        return viewPos + float3(0.2,0,0);}float4 ReprojectPS(FSQuadVS_InOut In) : COLOR{    float reprojDepth = 9999;    float reprojColor = 0;        float nearestColor = 0;    float nearestDistance = 9999;        float4 decodedCenter = DecodeBake(In.UV); // xyz = view, w = test pattern        float4 projectedCenter = mul(float4(decodedCenter.xyz,1), Proj);    projectedCenter /= projectedCenter.w;        for(float i=-63; i<64; i++) // note: brute force = bad, just a test    {        float2 sampleUV = In.UV + float2(i / BufferSize.x, 0);                // we assume in this test that the "color" is baked in w        // also, we assume that the scene fills the entire screen,        // we draw something everywhere...        float4 decoded = DecodeBake(sampleUV);                    float3 newView = ReprojectView(decoded.xyz);                float4 projectedNewView = mul(float4(newView,1), Proj);        projectedNewView /= projectedNewView.w;                float rowDist = abs(projectedNewView.x - projectedCenter.x);                // Check if the new sample covers our pixel        // note: al these tests can be made "fuzzy" by constructing        // a weighting function instead        if(rowDist < (2.0 / BufferSize.x))        {            if(reprojDepth>newView.z)            {                reprojColor = decoded.w;                reprojDepth = newView.z;            }        }                // We'll use this to fill the holes if any        // note: this is a very crude inpaiting method, something        // way better should be used for the method to work decently        float heuristicDistance = rowDist*rowDist / newView.z;        if(heuristicDistance < nearestDistance)        {            nearestColor = decoded.w;            nearestDistance = heuristicDistance;        }    }        // If we didn't find anything, we pull something from thin air...    if(reprojColor==0) reprojColor = nearestColor;    //return float4(decodedCenter.www,1);    //return float4(reprojColor.xxx,1);    return float4(reprojColor,decodedCenter.ww,1);}// -- Techniquestechnique Main <    string Script =         "Pass=Bake;"        "Pass=FullScreen;"    ;>{    pass Bake     <        string Script =            "RenderColorTarget0=Bake;"            "ClearSetColor=ClearParam;"            "Clear=Color;"            "Clear=Depth;"            "Draw=Geometry;";    >    {        ZEnable = true;        ZWriteEnable = true;                VertexShader = compile vs_3_0 GeomVS();        PixelShader = compile ps_3_0 BakePS();    }        pass FullScreen    <        string Script =            "RenderColorTarget0=;"            "Draw=Buffer;";    >    {        ZEnable = false;        ZWriteEnable = false;            VertexShader = compile vs_3_0 FSQuadVS();        PixelShader = compile ps_3_0 ReprojectPS(); //CopyPS();    }};