Nature Mort Doc

transcript

8/14/2019 Nature Mort Doc

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CHRISTIAN TJAHJONO

Documentation

Nature Mort Project

Description

The objective is to create the illusion of decay and rotting written in RenderMan Shading

Language, to Maya scene. A combination of displacement and surface shade will used todemonstrate this decay process.

After collecting a sequence of picture reference, I began with creating the base mesh inMaya and unwrap the uv so that it’s not going to be a trouble later if I export the obj file

into Mudbox. Also it will give you more control if I want to apply fur or hair in Maya by

crank-up the uv’s.

I start sculpting inside Mudbox to create a believable shape of fresh strawberry. I use the

photos reference to recreate the process of decaying. At the end I end up with 28 different

shape and texture of strawberry. After finish with the sculpting, bake all 28 displacementmaps and then bring all the alpha channel into Photoshop and compile everything in one

tiff file.

I use one of displacement maps to create the color maps in Photoshop by painting it from

scratch. Keep adding layers until you satisfied with the rotten maps as a final color maps.

I put all the color maps in one tiff file.

I use the texture channels from www.fundza.com to compile displacement and color

maps into cutter to be able to create and have more controls of your texture later in Maya.

In Maya I stated to import all the different base mesh in obj’s file and create a blendshapes for the animation purposes.

After you created the blend shape, now it’s the fun part! Start to load all the shader that

you created in cutter into Maya Renderman node’s.

After I satisfied with the look of my strawberry I applied a fur on to my strawberry. Then

start to animate the color, displacement and fur.

STRAWBERRY DISPLACMENT

PARAMETERS

Km = 0.0001 Overall displacement scaling factor.

UseShadingNormal = 1 Smooth shading surface normals give the polygonal data a smooth.

Time = 1 Appearance through time.

Hump = 0 The value output of the surface shader.

STRAWBERRY SURFACE

PARAMETERS

Ks = 1 The percentage of specular light in the scene

reflected by this surface.

Specular Color = The color of the specular illumination.

Time = 1 Appearance through time.

Hump = 0 The value output of the surface shader.

Displacement Shader Code

displacementStrawberry_Displace(float Km = .0001, /* displacement magnitute */

UseShadingNormals = 1, /* [0 or 1] */

time = 1; /* {0 1] */

string map = "";output varying float hump = 0)

{vector diff = normalize(N) - normalize(Ng);

normal n = normalize(N);

float tex;

if(map != "")

if(time <= 0.20) hump = mix(1, texture(map[0]), smoothstep(0,0.20,time)); else if(time >0.20 && time <= 0.4) hump = mix(texture(map[0]), texture(map[1]),

smoothstep(0.2,0.4,time)); else if(time > 0.4 && time <= 0.6) hump =

mix(texture(map[1]), texture(map[2]), smoothstep(0.4,0.6,time)); else if(time > 0.6 &&

time <= 0.8) hump = mix(texture(map[2]), 1 - texture(map[3]),smoothstep(0.6,0.8,time)); else if(time > 0.8)

hump = mix(texture(map[3]),

1 - texture(map[4]), smoothstep(0.8,1.0,time));

else if(time > 1.0)hump = mix(texture(map[4]),

1 - texture(map[5]), smoothstep(1.0,1.2,time));else if(time > 1.2)

hump = mix(texture(map[5]),

else if(time > 1.4)…………….

P = P - n * (hump - 0.5) * Km;

if(UseShadingNormals) N = normalize(calculatenormal(P)) + diff;

N = calculatenormal(P);

The Shader Code

surface

Strawberry_Surface(float Ks = 1,

time = 0;color hilitecolor = color (0,1,0),

specularcolor = (0,0,0);

string map = "";color blotch_color = 0;)

color surfcolor = 1;normal n = normalize(N);

normal nf = faceforward(n, I);

float tex;

if(map != "")

if(time <= 0.20)

tex = mix(1, texture(map[0]), smoothstep(0,0.20,time));else if(time > 0.20 && time <= 0.4)

tex = mix(texture(map[0]),

texture(map[1]), smoothstep(0.2,0.4,time));

else if(time > 0.4 && time <= 0.6)tex = mix(texture(map[1]),

texture(map[2]), smoothstep(0.4,0.6,time));else if(time > 0.6 && time <= 0.8)

tex = mix(texture(map[2]),1 - texture(map[3]), smoothstep(0.6,0.8,time));

else if(time > 0.8)

tex = mix(texture(map[3]),

// composite the texture map color over the backgroundsurfcolor = mix(blotch_color, Cs, tex);

Oi = Os;

Ci = Oi * Cs * surfcolor * specularcolor * Ka * Kd * Ks * diffuse(nf);}

Maps Images

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