CS代考程序代写 HW 4 Interpolation Modes
HW 4 Interpolation Modes
• App sets GZ_INTERPOLATE flag
• GZ_FLAT : flat shading (default – Shade using first vertex normal) • GZ_COLOR : vertex shading and color interpolation (Gouraud)
• GZ_NORMALS : normal interpolation and pixel shading (Phong)
• App sends triangle
– Transform norms with Xn (transform all of the norms)
• If GZ_FLAT :
• Compute color based on 1st vertex normal
• AsinHW3–usethesamecolorforalltrianglepixels
• Else:
• IfGZ_COLOR:
– compute color at verts, rasterize while interpolating RGB vertex colors
• IfGZ_NORMALS:
– rasterize while interpolating Normals and compute color at each pixel
– NOTE: MAKE SURE YOU “NORMALIZE” THE LENGTH OF THE INTERPOLATED NORMAL VECTOR AT EACH PIXEL BEFORE YOU EVALUATE THE SHADING EQUATION
Interpolation Examples
Image courtesy of Watt & Watt, Advanced Animation and Rendering Techniques
More Interpolation Examples
HW4 Details
● Add a shader to your Gz rendering library to support Flat -shading, Gouraud shading, and Phong shading
● The shading mode is set by selected an interpolation mo de
● The GZ_INTERPOLATE flag selects between flat shadin g (no interpolation), vertex color interpolation, and norm al interpolation.
● You will support two light types GZ_AMBIENT_LIGHT an d a directional light specified by GZ_DIRECTIONAL_LIG HT
● Both are of type GzLight (in Gz.h)
● The direction vector is only valid for directional lights and it is t he vector from the scene to the light in image-space
● Ambient light direction has no meaning – so it is ignored
HW4 Details (2)
● Only one ambient light is supported, but multiple directional lights are possible (u p to 10)
● Lights are specified by a call to GzPutAttribute()
● GzPutAttribute() must accept the following tokens/values:
● GZ_RGB_COLOR GzColor default flat-shade color
● GZ_INTERPOLATE int shader interpolation mode
● GZ_DIRECTIONAL_LIGHT
● GZ_AMBIENT_LIGHT
● GZ_AMBIENT_COEFFICIENT
● GZ_DIFFUSE_COEFFICIENT
● GZ_SPECULAR_COEFFICIENT
● GZ_DISTRIBUTION_COEFFICIENT
GzLight
GzLight (ignore direction) GzColor Ka reflectance GzColor Kd reflectance
GzColor Ks coef’s float spec power
HW4 Details (3)
●Values for GZ_INTERPOLATE
● GZ_FLAT 0 ●GZ_COLOR 1 ●GZ_NORMALS
/* flat shading uses first vertex normal */ /* interpolate vertex color */
2 /* interpolate normals */
●Gz.h defines a GzLight type since the application has to set up light s
●*** Note that you can use your existing LEE or DDA interpolation me thods for color or normal interpolation
● No need to invent a new method
HW4 Shading
Camera set
Color interpolation
Normal interpolation
Default camera
HW4 Flat Shading
Default camera
Camera set
HW4 teapot
● Modeling errors in the teapot normals ● Normals have inconsistent signs
line 2593
triangle
0.000281 3.000000 0.000844 0.000000 1.000000 0.000000 0.250000 0.000000
0.000750 3.000000 0.000750 0.000000 -1.000000 0.000000 0.500000 0.000000
0.242477 2.950782 0.242477 0.423818 0.800473 0.423818 0.500000 0.250000
similar issues at lines 2625, 2629, 2721, 2753, 2849, 2881, 2977, 3009
HW 4 Interpolation Modes
• App sets GZ_INTERPOLATE flag
• GZ_FLAT : flat shading (default – Shade using first vertex normal) • GZ_COLOR : vertex shading and color interpolation (Gouraud)
• GZ_NORMALS : normal interpolation and pixel shading (Phong)
• App sends triangle
– Transform norms with Xn (transform all of the norms)
• If GZ_FLAT :
• Compute color based on 1st vertex normal
• AsinHW3–usethesamecolorforalltrianglepixels
• Else:
• IfGZ_COLOR:
– compute color at verts, rasterize while interpolating RGB vertex colors
• IfGZ_NORMALS:
– rasterize while interpolating Normals and compute color at each pixel
– NOTE: MAKE SURE YOU “NORMALIZE” THE LENGTH OF THE INTERPOLATED NORMAL VECTOR AT EACH PIXEL BEFORE YOU EVALUATE THE SHADING EQUATION
Interpolation Examples
Image courtesy of Watt & Watt, Advanced Animation and Rendering Techniques
More Interpolation Examples
HW4 Details
● Add a shader to your Gz rendering library to support Flat -shading, Gouraud shading, and Phong shading
● The shading mode is set by selected an interpolation mo de
● The GZ_INTERPOLATE flag selects between flat shadin g (no interpolation), vertex color interpolation, and norm al interpolation.
● You will support two light types GZ_AMBIENT_LIGHT an d a directional light specified by GZ_DIRECTIONAL_LIG HT
● Both are of type GzLight (in Gz.h)
● The direction vector is only valid for directional lights and it is t he vector from the scene to the light in image-space
● Ambient light direction has no meaning – so it is ignored
HW4 Details (2)
● Only one ambient light is supported, but multiple directional lights are possible (u p to 10)
● Lights are specified by a call to GzPutAttribute()
● GzPutAttribute() must accept the following tokens/values:
● GZ_RGB_COLOR GzColor default flat-shade color
● GZ_INTERPOLATE int shader interpolation mode
● GZ_DIRECTIONAL_LIGHT
● GZ_AMBIENT_LIGHT
● GZ_AMBIENT_COEFFICIENT
● GZ_DIFFUSE_COEFFICIENT
● GZ_SPECULAR_COEFFICIENT
● GZ_DISTRIBUTION_COEFFICIENT
GzLight
GzLight (ignore direction) GzColor Ka reflectance GzColor Kd reflectance
GzColor Ks coef’s float spec power
HW4 Details (3)
●Values for GZ_INTERPOLATE
● GZ_FLAT 0 ●GZ_COLOR 1 ●GZ_NORMALS
/* flat shading uses first vertex normal */ /* interpolate vertex color */
2 /* interpolate normals */
●Gz.h defines a GzLight type since the application has to set up light s
●*** Note that you can use your existing LEE or DDA interpolation me thods for color or normal interpolation
● No need to invent a new method
HW4 Shading
Camera set
Color interpolation
Normal interpolation
Default camera
HW4 Flat Shading
Default camera
Camera set
HW4 teapot
● Modeling errors in the teapot normals ● Normals have inconsistent signs
line 2593
triangle
0.000281 3.000000 0.000844 0.000000 1.000000 0.000000 0.250000 0.000000
0.000750 3.000000 0.000750 0.000000 -1.000000 0.000000 0.500000 0.000000
0.242477 2.950782 0.242477 0.423818 0.800473 0.423818 0.500000 0.250000
similar issues at lines 2625, 2629, 2721, 2753, 2849, 2881, 2977, 3009
More teapots
