Final Presentation

https://www.dropbox.com/s/pgvuc8c365mheid/FinalDemo-WebGL%20pathTracer.ppt

Project5

Part1 Globe:

Implemented

• Bump mapped terrain
•     float center = texture2D( u_Bump, v_Texcoord + vec2( -u_time*0.8, 0.0 ));
      float right = texture2D( u_Bump, v_Texcoord+ vec2( -u_time*0.8, 0.0 ) + vec2(1.0/1000.0, 0.0) );
      float top = texture2D( u_Bump, v_Texcoord + vec2( -u_time*0.8, 0.0 )+ vec2(0.0, 1.0/500.0) );
  
      vec3 perturbedNorm = normalize( vec3(center - right, center - top, 0 .2) );
      vec3 bumpNorm = normalize(eastNorthUpToEyeCoordinates(v_positionMC, normal)* perturbedNorm);
  
      float BumpDiffuse = max( dot(u_CameraSpaceDirLight, bumpNorm), 0.0 );

• Rim lighting to simulate atmosphere

    float rimFactor = dot(v_Normal, v_Position) + 1;

• Nighttime lights on the dark side of the globe

• Specular mapping
• Moving clouds(from west to east)
• Orbiting Moon with texture mapping

Part2 SSAO(Screen Space Ambient Occlusion):

gatherOcclusion：
        float distance =  length( occluder_position - pt_position );
        float overhead = dot( pt_normal, normalize( occluder_position - pt_position ) );
        float planar = 1.0 - abs( dot( pt_normal, occluder_normal ) );
        return planar*max( 0.0, overhead )*( 1.0/(1.0 + distance) ) ;

regularSample：
        vec2 occludePos = texcoord + vec2( i, j )*REGULAR_SAMPLE_STEP;
        vec3 occPos = samplePos(occludePos);
        vec3 occNorm = normalize( sampleNrm(occludePos) );
        accumOcclusion += gatherOcclusion( normalize(normal), position, occNorm, occPos ) ;


Part3 Vertex Pulsing
float displacement = scaleFactor * (0.5 * sin(Position.y * u_frequency * u_time) + 1);
vec3 newPosition = Position + displacement * Normal;

Image Processing/ Vertex Shading

Video

Pat1
Original picture:

Fetures implemeted:

•  Image negative: vec3(1.0) - rgb

•  Gaussian blur: GaussianBlurMatrix = 1/16[[1 2 1][2 4 2][1 2 1]]

•  Grayscale: vec3 w = vec3(0.2125, 0.7154, 0.0721); luminace = dot(rgb, W);

•  Edge Detection: Sobel-horizontal = [[-1 -2 -1][0 0 0 ][1 2 1]]; Sobel-vertical = [[-1 0 1][-2 0 2 ][-1 0 1]].

• Toon shading

Optional features:

• Pixelate: define the pixel size(by using the picture size); Get the new coordinates by6 multiply the pixel size with the pixel index. Pixel indices are calculated by dived the original texture coordinates by pixel size.

• Brightness: u = (rgb.r + rgb.g + rgb.b)/3;

• Contrast: (m-a)/(n-a) vs m/n

• Night Vision: Only multiplied by green color;

 

Part2:

Sea wave:

float s = sin(pos.x*2PI + time);

        float t = cos(pos.y*2PI + time);

        height = sin(sqrt(s^2 + t^2 ))/sqrt(s^2 +t^2 );

Raterizer -- some triangles are missing

Optional feature I chose are:

• backface culling

• interactive camera

The rasterization doesn't looks right, some faces are missing:

Back-face culling

Video：

Path Tracer--Got basic features right

• Anti-aliasing:

Added a random offset when each ray is generated.

   

I don't know why there are white lines on the white sphere.

• Depth of Field:

 Get the focused plane and shake the camera certain random amount in X and Y direction.

• Short Demo: 

Path tracer--Got the color right

I made mistakes in the Accumulate function for color accumulation.
Here is the corrected one rendered scene I got:

Path Tracer -- Always get flat shading

I implemented:

• calculateBSDF
• calculateFresnel
• calculateTransmissionDirection.
• stream compaction

But the rendered picture I got is always flat shading. And the color doesn't looks right.

The problem is that in remove_if function I accidentally remove all the rays that need to continue tracing. For the colors, that is because I used plus instead of multiply.

Correctted that I got this: