AR project proposal form

Folks,

If you would like to propose an AR project as an alternative to progs 4 and 5 this semester, please use this form to submit it. Please do so by Friday evening.

ProfW

Program 4, 2020: Texture and Transparency (final)

Partial Due: 11:59pm, Friday October 23

Final Due: 11:59pm, Friday October 30 

Goal: In this assignment you will learn about rendering textured and transparent models using the WebGL rasterization API.

Submission: Submit your assignment using this Google Form.


BASIC GRADING:
The main components of this programming assignment are:
  • 5% Part 0: partial feedback
  • 5% Part 1: properly turned in assignment
  • 30% Part 2: render the input triangles and ellipsoids, textured but without lighting
  • 30% Part 3: render using both lighting and texture
  • 30% Part 4: render using lighting, texture and transparency
  • Participation: Receive participation credit (outside of this assignment) for posting images of your progress, good or bad, on the class forum!

General:
You will render triangles and ellipsoids, described in the same sorts of JSON input files used in the third assignment. We will again test your program using several different input files, so it would be wise to test your program with several such files. The input files describe arrays of triangles and ellipsoids using JSON. Example input files reside at https://ncsucgclass.github.io/prog4/triangles.json and https://ncsucgclass.github.io/prog4/ellipsoids.jsonUse these URLs in hardcode as the locations of the input triangles and ellipsoids files — they will always be there. While testing, you should use a different URL referencing a file that you can manipulate, so that you can test multiple triangles and ellipsoid files. These files have been improved to include texture file names and alpha values. The triangles files also contain vertex normals and uv coordinates. 

For this assignment, we have made additions to the file format supporting a transparency alpha, texture filenames and texture coordinates. All textures will reside at the same URL as the model input files. For example, if the triangles.json file makes a reference to texture1.jpg, then it will reside at https://ncsucgclass.github.io/prog3/texture1.jpg. 

When you load texture images, you can only load them from your own server (hosting both your code and your images), or from a server that explicitly allows cross-origin access, like github.com. To access images from such an allowing server, set the image's crossOrigin attribute to "Anonymous". You can find more detail hereTexture loads happen asynchronously (on a different thread from your javascript), so your texture may not appear immediately. We recommend that you load a one pixel "dummy" texture locally to avoid runtime errors in the meanwhile, as shown here.

We are providing a shell in which you can build your code. You can run the shell here, and see its code here. This shell is a correct implementation of program 3, which also loads an image (which can ultimately become a texture) as the canvas background. Default viewing parameters are the same as in program 3.

This is an individual assignment, no exceptions. You should code the core of this assignment yourself. You may not use others' code to implement texturing, blend texture with lighting, or implement transparency. You may use math, matrix and modeling libraries you find, but you must credit them in comments. You may recommend libraries to one another, speak freely with one another about your code or theirs, but you may never directly provide any code to another student. If you are ever uncertain that the advice you want to give or the code you want to use is permissible, simply ask me or the TA.

Part 0: Partial feedback
You should turn in an "ugly," incomplete version of your program by Friday October 23. If you simply turn in a copy of our shell, you will get half credit (2.5%). If you actually do something to visibly change the shell's output, you will receive full marks (5%), and receive comments on what you've done. We will not otherwise grade the assignment at this point, only comment on it.

Part 1: Properly turned in assignment
Remember that 10% of your assignment grade is for correctly submitting your work! For more information about how to correctly submit, see this page on the class website.

Part 2: Render the input triangles and ellipsoids, textured but without lighting
Use WebGL to render unlit triangles and ellipsoids, giving each fragment its textured color. Do not perform lighting. You will have to use the fragment shader to find the appropriate color in the texture. UV coordinates are provided with triangle sets, but must be generated for ellipsoids. We suggest latitude and longitude be mapped to [0,1].

Part 3: Render with texture and lighting
Improve your renderer to shade fragments by mixing texture with lighting. A simple approach is modulation, which uses the lit fragment Cf to scale the texture Ct: C = CfCt. You can find more ideas hereToggle across at least two light/texture blending modes (e.g. replace and modulate) when the b key is pressed.

Part 4: Render with texture, lighting and transparency
Improve your renderer further by adding transparency (alpha) to its rendering. To avoid transparent objects occluding other objects, you will have to first render opaque objects with z-buffering on, then transparent objects with the z-write component of z-buffering off (gl.depthMask(false)).


EXTRA CREDIT GRADING: 
The extra credit components we suggest for this assignment are:
  • 461: 1%  — 561: ½% — support transparent textures
  • 461: 1%  — 561: ½% — support multitexturing
  • 461: 2%  — 561: 1% — improve transparency correctness with the painter's algorithm
  • 461: 5%  — 561: 3% — improve transparency correctness further with a BSP tree
Other extra credit is possible with instructor approval. You must note any extra credit in your readme.md file, otherwise you will likely not receive credit for it.

Extra credit: support transparent textures
Make use of the alpha component in textures during rendering. Use this to given your models irregular outlines. There are textures in the assignment repo that will produce this effect.

Extra credit: support multitexturing
Combine multiple textures when performing lighting of a model. For example, you could perform light mapping. We will include a texture in the assignment repo that supports light mapping.

Extra credit: improve transparency correctness with a partial sort
Sort your transparent triangles by depth to make transparency more correct. You must sort before rendering. You may have to issue a separate draw calls to ensure gpu parallelism does not undo your ordering.

Extra credit: improve transparency correctness further with a BSP tree
Sort your transparent triangles with a BSP tree to improve transparency further. This will split triangles when they intersect.

Target output for program 3

 Hey folks,

Here is the target output for program 3, the ellipsoids url is still the same as in description, the values have been modified a bit. 





Program 3, 2020: Rasterization

Partial Due: 11:59pm, Friday Oct 2

Final Due: 11:59pm, Friday Oct 9

Goal: In this assignment you will practice basic modeling and implement transforms and lighting on 3D objects using the WebGL rasterization API.

Submission: Submit your assignment using this Google Form.


BASIC GRADING:
The main components of this programming assignment are:
  • 5% Part 0: partial feedback
  • 5% Part 1: properly turned in assignment
  • 10% Part 2: render the input triangles, without lighting
  • 20% Part 3: model and render the input ellipsoids, without lighting
  • 20% Part 4: light the ellipsoids and triangles
  • 15% Part 5: interactively change view
  • 5% Part 6: interactively select a model
  • 20% Part 7: interactively transform the ellipsoids and triangles
  • Participation: Receive participation credit (outside of this assignment) for posting images of your progress, good or bad, on the class forum!

General:
You will only render triangles and ellipsoids in this assignment, described in the same sorts of JSON input files used in the first. We will test your program using several different input files, so it would be wise to test your program with several such files. The input files describe arrays of triangles and ellipsoids using JSON. Example input files reside at https://ncsucgclass.github.io/prog3/triangles.json and https://ncsucgclass.github.io/prog3/ellipsoids.json. When you turn in your program, you should use these URLs in hardcode as the locations of the input triangles and ellipsoids files — they will always be there. While testing, you should use a different URL referencing a file that you can manipulate, so that you can test multiple triangles and ellipsoid files. Note that browser security makes loading local files difficult, so we encourage you to access any input files with HTTP GET requests.

We provide a small shell in which you can build your code. You can run the shell here, and see its code and assets here. The shell shows how to draw triangles using WebGL without any model or view transform, and how to parse the input triangles.json file. It also shows how to use animation callbacks to render multiple image frames.

The default view and light are as in the first assignment. The eye is at (0.5,0.5,-0.5), with a view up vector of [0 1 0] and a look at vector of [0 0 1]. Locate the window a distance of 0.5 from the eye, and make it a 1x1 square normal to the look at vector and centered at (0.5,0.5,0), and parallel to the view up vector. With this scheme, you can assume that everything in the world is in view if it is located in a 1x1x1 box with one corner at the origin, and another at (1,1,1). Put a white (1,1,1) (for ambient, diffuse and specular) light at location (-0.5,1.5,-0.5).

This is an individual assignment, no exceptions. You should code the core of this assignment yourself. You should code the core of this assignment yourself. You may not use others' code to transform or project models or perform Blinn-Phong lighting. You may use math, matrix and modeling libraries you find, but you must credit them in comments. You may recommend libraries to one another, speak freely with one another about your code or theirs, but you may never directly provide any code to another student. If you are ever uncertain if the advice you want to give or code you want to use is permissible, simply ask me or the TA.

Part 0: Partial feedback
You should turn in an "ugly," incomplete version of your program by Friday October 2. If you simply turn in a copy of our shell, you will get half credit (2.5%). If you actually do something to visibly change the shell's output, you will receive full marks (5%), and receive comments on what you've done. For example, if you turn in a complete, first attempt at the assignment, we will tell you in text what is working, and what isn't, so you can raise your final score. We will not otherwise grade the assignment at this point, only comment on it.

Part 1: Properly turned in assignment
5% of your assignment grade is just for correctly submitting your work! For more information about how to correctly submit, see this page on the class website.

Part 2: Render the input triangles, without lighting
Use rasterization to render unlit triangles, giving each triangle its unmodified diffuse color (e.g, if the diffuse color of the triangle is (1,0,0), every pixel in it should be red). You will have to use vertex shaders to perform viewing and perspective transforms, and fragment shaders to select the diffuse color. We recommend the use of the glMatrix library for creating these transforms.

Part 3: Render the input ellipsoids, without lighting
Use rasterization to render unlit ellipsoids, giving each ellipsoid its unmodified diffuse color. There are no ellipsoid primitives available in WebGL, so you will have to build an ellipsoid out of triangles, then transform it to the right location and size. You can do this statically with a hardcoded sphere model, or procedurally with a latitude/longitude parameterization. You then scale this sphere to match its ellipsoidal parameters. Again you will have to use vertex shaders to perform viewing and perspective transforms, fragment shaders to select color.

Part 4: Light the ellipsoids and triangles
Shade the ellipsoids and triangles using per-fragment shading and the Blinn-Phong illumination model, using the reflectivity coefficients you find in the input files. Use triangle normals during lighting (which will reveal faceting on your ellipsoids). Your fragment shaders will perform the lighting calculation.

Part 5: interactively change view
Use the following key to action table to enable the user to change the view:
  • a and d — translate view left and right along view X
  • w and — translate view forward and backward along view Z
  • and e — translate view up and down along view Y
  • A and D — rotate view left and right around view Y (yaw)
  • W and — rotate view forward and backward around view X (pitch)
To implement these changes you will need to change the eye, lookAt and lookUp vectors used to form your viewing transform.

Part 6: Interactively select a model
Use the following key to action table to interactively select a certain model:
    • left and right — select and highlight the next/previous triangle set (previous off)
    • up and down — select and highlight the next/previous ellipsoid (previous off)
    • space — deselect and turn off highlight
    A triangle set is one entry in the input triangle array. To highlight, uniformly scale the selection by 20% (multiply x y and z by 1.2). To turn highlighting off, remove this scaling. You will have to associate a transform matrix with each ellipsoid and triangle to maintain state, and apply this transform in your vertex shaders. glMatrix will also be helpful here.

    Part 7: Interactively transform models
    Use the following key to action table to interactively transform the selected model:
    • k and ; — translate selection left and right along view X
    • o and — translate selection forward and backward along view Z
    • and p — translate selection up and down along view Y
    • K and : — rotate selection left and right around view Y (yaw)
    • O and — rotate selection forward and backward around view X (pitch)
    • and P — rotate selection clockwise and counterclockwise around view Z (roll)
    Translate the model after you rotate it (so the model rotates around itself), and after the highlighting scale (see above, so the model doesn't translate as it scales).


    EXTRA CREDIT GRADING: 
    The extra credit components we suggest for this assignment are below:
    • 461: 1% — arbitrarily sized viewports
    • 461: 1% — off-axis and rectangular projections
    • 461: 1% — multiple lights at arbitrary locations
    • 461: 3% — 561: 1% — smooth shading with vertex normals
    Students in 561 should not perform components that will not earn extra credit. Other components are possible with instructor approval. You must note any extra credit in your readme.md file, otherwise you will likely not receive credit for it.

    Extra credit: Arbitrarily sized viewports 
    Accept a new square canvas (viewport) width/height through your UI. Size your canvas to match.

    Extra credit: Support off-axis and rectangular projections 
    Accept new window parameters in viewing coordinates through your UI (left, right, top, bottom). Adjust your projection matrix to this new window, and render the scene.

    Extra credit: Multiple and arbitrarily located lights
    Read in an additional lights.json file that contains an array of objects describing light location and color. Note that these lights will have distinct ambient, diffuse and specular colors. Render the scene with all of these lights. You can find an example lights.json file here. Assume that the input lights file will always reside at this URL when you turn in your code.

    Extra credit: Smooth shading with vertex normals 
    Using only triangle normals, your ellipsoids and other curved shapes will look disappointingly faceted. To represent curvature more accurately, you need vertex normals. As you generate ellipsoids from spheres, create vertex normals by subtracting the surface point from the sphere center. When you read in triangles, check for vertex normals in the input file. As you apply the composited modeling, viewing and projection matrices to your vertices, apply the inverse transpose of the modeling transform to your vertex normals. During lighting, use these normals rather than the face normal. The rasterizer will interpolate them for you.

    Target output for prog 2

     Hey folks,


    Here is the correct output image for program 1.



    Extra credit: CG innovators and diversity

    Hey folks,

    Most significant figures in computer graphics history were white men. For 1% of extra credit, you may research someone a little different, and present a 5 minute report on them in one of our studios. To present such a report, schedule the studio time for it using our report calendar (for 461, for 561). Also, prepare a short Google Slides presentation, and upload it using this form.

    You can find suggestions on who you might research in my own lectures (e.g., Bui Tong Phong, Dorothea Jameson, and Lillian Schwarz), or in our wiki entry on women in CG — but feel free to find someone else! You may report again one someone already reported, but try to highlight something different: five minutes certainly doesn't allow a complete report. These people need not have retired, they may still be quite active in the field. If you have trouble finding someone new, don't be surprised, there weren't many. 

    In your report, you need not give a full bio. Just introduce them briefly, then go into some aspect of their career in CG. For example, you can discuss an important paper or other contribution to the field. You might also reach out to them via email, have short discussion with them, and report on what you learned. 

    I look forward to your reports!

    ProfW

    Program 2 2020: Intro to WebGL

     Due: 11:59pm, Friday Sep 18


    Goal: In this assignment you will focus on gaining basic understanding of the WebGL rasterization API, by learning how to render and manage a few triangles.

    Submission: Submit your assignment using this Google Form.


    GRADING:
    This assignment is a forgiving introduction to WebGL, with correspondingly forgiving grading. The main components of this programming assignment are:
    • 25% Part 1: attempt improvement of vertex and index arrays
    • 25% Part 2: render input triangles correctly
    • 25% Part 3: attempt improvement of shader to handle parameters
    • 25% Part 4: triangles in input color
    • Participation: Receive participation credit (outside of this assignment) for posting images of your progress, good or bad, on the class forum!

    General:
    You will only render triangles in this assignment, described in the same sorts of JSON input files used in the first. We will test your program using several different input files, so it would be wise to test your program with several such files. The input files describe arrays of triangles using JSON. An example input file resides at https://ncsucgclass.github.io/prog2/triangles.json. When you turn in your program, you should use this URL in hardcode as the location of the input triangles file — it will always be there. While testing, you should use a different URL referencing a file that you can manipulate, so that you can test multiple triangles files. Note that browser security makes loading local files difficult, so we encourage you to access any input files with HTTP GET requests.

    We provide a small shell in which you can build your code. You can run the shell here, and see its code and assets here. The shell shows how to draw triangles using WebGL, treating them all the same way. It also shows how to parse the input triangles.json file.

    We are using webGL's default view setup, with the eye at the origin, and the window from -1 to 1 horizontally and vertically.

    This is an individual assignment, no exceptions. That said, we encourage you to help one another with this assignment. Feel free to suggest how other students might solve problems, and to help them debug their code — just don't write their code for them. The code you turn in should still be your own (except for the shell). This is a simple assignment, and should not need other third party libraries. As always, if you are ever uncertain if the help you want to give or the code you want to use is permissible, simply ask me or the TA. For information about how to correctly submit, see this page on the class website.

    Parts 1 & 2: Attempt to improve vertex and index array, and render triangles correctly
    For these parts of the assignment, your goal is to display the input triangles in the correct position. The shell only renders the first set of triangles, in solid white. You must change the code to display all the triangles, improving two arrays: one that describes the vertices and their attributes, and another that describes the triangles by listing their vertex indices. If you make a solid attempt at improving these arrays, you will receive full credit for Part 1. If you correctly render all the triangles in white, you will earn full credit for Part 2.

    Parts 3 & 4: Attempt to improve the shader, and render the input colors correctly
    For these parts of the assignment, your goal is to color the input triangles with their diffuse color. The shell includes basic shader code that renders everything in white. You must change the shader to accept and use a parameter, and the code to send the shader a different value for the parameter for each triangle set. If you make a solid attempt at this, you will receive full credit for Part 3. If you correctly render each triangle set with its unique color, you will earn full credit for Part 4.