Dandelions - Results

I'll probably continue to work on this (most likely) after this course. But in the scope of this course, this project is done, built, submitted. Done. Finished. A long report has been written and submitted. Its over.

There's a lot of things I'd love to do with it later, but I thought I'd post some images of how it looks these days.

One Dandelion with attributes listed 

A similar dandelion, with different attributes

A lit field. Looks wonky.

caption

Field, with details

Ray Tracer Part 7 - Tone Reproduction

For the final part of the Ray Tracer, Tone Reproduction, using Reinhard and Ward Compression techniques, were implemented.

Ward Compression

Ward, 1 nit

Ward, 10 nits

Ward, 100 nits

Ward, 1000 nits

Reinhard Compression

This portion I've had a lot of issues with. I realize that in Reinhard, the Max Luminance is supposed to have very little (if any) effect on the luminance of the scene.  Unfortunately, I can't find where in my code this seems to go wrong. The equations seem almost identical to me, and I'm simply at a loss. Instead, I got these interesting images.

My code was as follows (per pixel):
// Part A of Compression            
pixels[y][x].l_red = ( kv * pixels[y][x].l_red ) / log_avg_lum;            
pixels[y][x].l_green = ( kv * pixels[y][x].l_green ) / log_avg_lum;            
pixels[y][x].l_blue = ( kv * pixels[y][x].l_blue ) / log_avg_lum;    
       
// Part B of Compression            
pixels[y][x].l_red = ((pixels[y][x].l_red)/ (1 + pixels[y][x].l_red)) *ld_max; pixels[y][x].l_green = ((pixels[y][x].l_green)/ (1 + pixels[y][x].l_green)) * ld_max;            
pixels[y][x].l_blue = ((pixels[y][x].l_blue)/ (1 + pixels[y][x].l_blue))*ld_max;

// Apply Device Model            
pixels[y][x].l_red = pixels[y][x].l_red / ld_max;            
pixels[y][x].l_green = pixels[y][x].l_green / ld_max;            
pixels[y][x].l_blue = pixels[y][x].l_blue / ld_max;            

// Print Point to Screen            
glColor3f( pixels[y][x].l_red, pixels[y][x].l_green, pixels[y][x].l_blue ); glVertex2d( x, y );

Reinhard, 1 nit

Reinhard, 10 nits

Reinhard 100 nits

Reinhard 1000 nits

Reinhard, with different Key-Value pixel selection

I was still able to use a key-value pixel selection for this, which showed a little better effect. All pictures were taken with a Lmax of 1, to simulate if my Reinhard above was working properly.

Reinhard, Key Value at x=400 y=400

Reinhard, Key Value at x=100 y=100

Reinhard, Key Value at x=250 y=250

Ray Tracer Part 6: Transmission

This part of the ray tracer is adding a transmission ray to the front sphere.

Renderman Images

For this assignment, we were asked to play around with Renderman and make some changes to a given image. One image was to display changes of the different attributes of the initial image, and the other image was to change the shaders (downloaded & modified, or a shader of your own).

On the attribute-change image, I changed the color of the plastic ball, spread out the wooden pattern with less roughness and more ring-scale, and increased the brick-width and mortar thickness of the brick floor.

For the image with new shaders, the wall is a stucco shader from the shader repository, in which I inverted the displacement of the stucco giving it a more cement-like feel. The ball is shaded with "funkyglass", which I changed to have a more transparent feel, darker edges, and more colors; resulting in a oil-bubble like image. The shader on the bottom was one I wrote myself, using the noise function to mix between an opacity value and a given color. 

Attribute Changes on original image

Shader changes on original image

For the extra assignment, we were to make a separate image and different shaders. The below is my submission of the Towers of Hanoi. For this submission, I used the provided "plastic" and "wood2" surface shaders, and modified some of their attributes. I also retrieved a "superplank" surface shader for the floor and "KMPuffyclouds" for the sky. I then also created my own "grass" displacement shader, and added my "coals" shader from the above shader image in a green color to make a better grass effect.

Towers of Hanoi

Ray Tracer Part 5: Reflection

Single Reflection Ray on Mirrored Sphere

This assignment's focus was adding reflection to the Ray Tracer. Due to the size of my floor, I moved the reflective sphere around a little for a more aesthetic reflection. I also moved the light sources slightly to the center so the shadows would reflect in the back sphere.

I also implemented using multiple reflection rays to approximate a BRDF. Below you can see the results of some of these experiments.

 

6 reflection rays, in a cone-radius
of .005



8 reflection rays, with a cone-radius of .01



8 reflection rays, with a cone-radius
 of .005


 

Dandelions - Getting the Dome

Its weird how just seemingly small concepts can move you from having something look weird to looking about right. It's not perfect, but it makes you feel on the right track. This is the path to making the dandelion move from a wad of cotton balls on sticks to something looking like a dandelion.

First off, I created randomly generated (and removed) dandelions to go into my field. Each one a separate and new instance of a flower.

 

The next step was to try and figure out how to make it a little more realistic. After some exciting searching and browsing pictures of dandelions, I tried to make the colors of the different elements closer to what they actually were. I learned that the stalks of each flower were more orangey, and the seedlet stalks were a darker green. I also shrank the size of the balls on the tips of each seedlet. Then, enter the hairs. They aren't curved yet, but standing straight still created a nice effect.

 



 

After further research, I decided to make the spheres of the flower closer to the dome-like structure the dandelions seem to have. From playing around with how the dome should act, I got to a point resulting like this:

 



I liked the domey-ness, and decided to keep up with this a bit longer. The below images are at a smaller geodesic tessellation to better see what the structure of the dandelions looks like.

Ray Tracer Part 4 - Procedural Shading

For this assignment, we had to add a pattern/texture to the floor of the scene. At different points of intersection, the floor is now different colors.

Initially, the pattern was a checkered Red/Yellow floor, as shown below:

Afterwards, as an "extra", I added another pattern. Now the pattern on the floor is a diagonal, as shown below.

I also allowed for an easy way to make the stripes and grid go at smaller and larger sizes, as shown below.