Additional Examples

 

§  Line-Sphere Intersection:

o   Here is the source

o   Here is the accompanied diagram

 

Some of the following examples are based on older versions of the libraries. In all cases, the idea remains the same though.

1. Problem with Hardware Shading: Some examples of confusing hardware shading problems. (Download Source Code)

2. Drawing 2D and 3D in the same window: Pay attention to DrawOnlyHandler::DrawGraphics(), after we are done drawing 3D is where all the 2D stuff happens. (Download Source Code)

3. Working with 2D and 3D Windows: Check on 2D Control Window to see the 2D view of the 3D world. In the 2D window, you can LMB click and drag either the teapot or the plane. The 2D window is like a 2D plane for supporting UI.  (Download Source Code)

4. Shadow Reflection and Stencil: We will discuss this in class! (Download Source Code)

5. Interesting Texture Effects:

o    Draw textures: (here is the source code)

1.       TdrawTexture class: now sub-class from Ttexture ….

    1. CreateD3DTexture: creating a 2D array of number, _and_ creating something in the D3D pipe!!
    2. UpdateTexture: Copy our 2D array into the pipe!!
    3. DrawCircleInTexture: draw circle in the 2D array of number!!

2.       Tworld: for any primitive that we can display textures (primitives with area: i.e. Tfillable): we have these new attributes:

    1. Two DrawTextures: in the Tworld constructor, we need to pass in Td3dDrawable … why do we need to pass into two drawables?
    2. TdrawTexture::Update: notice in Tworld::Update(), we are calling the TdrawTexture update …

o    Bubble texture: (here is the source code): simple tiny changes in TdrawTexture::UpdateTexture(), now instead of simply copy my 2D numbers into the hardware … I did a little bit of a trick … floating my texture and enlighten things a little … ok, pretty lame bubbles, but kind of interesting isn’t it? Now .what if I can control what is in the buffer, such that …

 

o    Fire Texture: (here is the source code):

  1. TupwardEffect class: basically … take color (index) and smear it upwards decrease as we go ….
  2. TfireTexure and TsmokeTexture: different color table to get different effects.

 

6. Fog: purely based on distance to camera. If you have ore than one views, the result looks strange! (here  is the source code).

7. X-Ray-light: now we are really hacking! I will talk about this in class. (here is the source code).

 

SimpleShader: almost the simplest vertex/pixel shader. Notice:

1.      Compare and contrast to Tutorial_A.1 on Page 490 from the textbook, see that we do not need to program the rendering pipeline anymore!

2.      We can load different “effects”: GrafxWindowD3D.cpp:: line 37.

3.      We can verify uv values are linearly interpolated after vertex shader and interpolated result is passed into the pixel shader.

4.      Effects parameter setting (e.g., effect->SetTexture()) has almost no error checking! We can call this function even if our effect has no support for texture! This is pretty cool, you can do almost anything you want, this is very annoying because compiler and/or run time is not looking for potential errors for us (setting texture when working with the simple shader)

5.      Nomrals are set up to point away from the center of the square (and has no y-components) We can load different “effects”. In NdotL shader, this would mean all pixels should be shaded to black (NdotL will equal to zero). But, linear interpolation is occurring and we can actually verify the results!

6.      Notice normal’s transform is different from that of the positions (with Inverse Transpose).

 

PixelPhong: integrate Vertex/Shader into our library (almost correct), and re-implement default phong illumination pipeline with vertex and pixel shader. Notice:

1.      UWB_LightingEffects:

a.       Supports 4 light sources, notice the difference! Phong is computed for each pixel rather than once per vertex!

b.      Texture is added to the illumination effect: one alternative would be to use the texture as replacement for diffuse material.

c.       Alpha term is always set to 1: this stop blending from working. A simple fix would be to assign material diffuse’s alpha value to the output. Alternatively, we can retain the phong illumination result for the alpha channel, can be cool?

2.      Effect as resources: effect files are “just like” texture and mesh files, we can take advantage of our “resource management” system to load/store the effect:

a.       D3D_Resources folder: D3DEffectResource, just like texture and mesh, we need to read the resource into the memory.

b.      D3D_GraphicsSystem folder:

                                                              i.      D3DGraphicsSystem class, we create a new effect resource table.

                                                            ii.      D3DGraphicsSystem_Effect.cpp: support setting of effect parameters, notice we support a super set of most of the parameters we need for illumination computation (e.g., always try to set material, always try to set texture, etc.)

c.       Other effect parameters: Light – done in D3D_Light class. Always set all 4 light sources.

d.      Other effect parameters: Camera Position: set in WindowHandler::DrawGraphics()

e.       Drawing with effect: D3D_DrawHelper gets the “current effect” from GraphicsSystem and renders with GraphicsSystem’s current.

f.       Should do: create effect as a attribute in Primitive such that each primitive has its own effects, this will make handling of effects identical to texture, much more general (and should get ride of the GraphicsSystem current effect).

3.      Known bugs:

a.       MeshArrow is not drawing correctly, I am not sure why yet.

b.      After loading of texture, effect loading will fail. I am not sure why.