OutViewDir = vecViewPos - mul(InPos, matWorld) įloat4 Ambient = AmbientIntensity * vecAmbient įloat4 Diffuse = DiffuseIntensity * SunColor * saturate(dot(-vecSunDir, InNormal)) Calculate a vector from the vertex to the view: Pass the texture coordinate to the pixel shader: OutNormal = normalize(mul(InNormal, matWorld)) Transform the normal from object space to world space: Transform the vertex from object space to clip space: MipFilter = Linear // required for mipmapping Sampler ColorMapSampler = sampler_state // Color map sampler. Application fed data:Ĭonst float4x4 matWorldViewProj // World*view*projection matrix.Ĭonst float4x4 matWorld // World matrix.Ĭonst float4 vecAmbient // Ambient color.Ĭonst float4 vecSunDir // The sun light direction vector.Ĭonst float4 vecViewPos // View position. Static const float4 SunColor = // Color vector of the sunlight. Static const float SpecularPower = 8.0f // The specular power, used as 'glossiness' factor. Static const float SpecularIntensity = 2.0f // The intensity of the specular light. Static const float DiffuseIntensity = 1.0f // The intensity of the diffuse light. Static const float AmbientIntensity = 1.0f // The intensity of the ambient light. We then raise the result to a power n which makes the highlight harder or softer.įinal Color = (Diffuse Light + Ambient Light + Specular Light) * Diffuse Color Implementation // Tweakables: This time we need the difference between the view vector and the reflection vector. As with diffuse lighting, we will use the dot product to calculate the cosine of the angle difference between the two vectors. This results in a vector pointing from the vertex to the camera (see "Subtracting Vectors" inĪppendix B). The view vector V is calculated by subtracting the vector world position from the camera position: The reflection vector R is calculated with the following formula: The angle between the reflection vector and view vector. If the angles are similar, the surface will be lit brightly, if they are far off, no specular light is reflected from the surface into the camera and only the diffuse and ambient light will be visible on this pixel. This reflection vector R is compared to the view direction vector. This vector is calculated from the light direction vector and the normal of the We will use a reflection vector that contains the direction of the light after it has bounced off We will use the Phong specular lighting model developed by Bui Tong Phong. There are several lighting models for simulating specular reflectance. The model thus affords a rational explanation for the off-specular peak phenomenon in terms of mutual masking and shadowing of mirror-like, specularly reflecting surface facets.Shader Workshops Workshop 3: Specular Lightingįor simulating shiny/polished surfaces the algorithm must also take into account the location of the viewer. Moreover, the analysis successfully predicts the off-specular maxima in the reflection distribution which are observed experimentally and which emerge as the incidence angle increases. The angular distributions of reflected flux predicted by the analysis are in very good agreement with experiment for both metallic and nonmetallic surfaces. The effects of shadowing and masking of facets by adjacent facets are included in the analysis. #Specular reflection plus#Specular reflection from these facets plus a diffuse component due to multiple reflections and/or internal scattering are postulated as the basic mechanisms of the reflection process. The analytical model assumes that the surface consists of small, randomly disposed, mirror-like facets. The directional distribution of radiant flux reflected from roughened surfaces is analyzed on the basis of geometrical optics. Note: Author names will be searched in the keywords field, also, but that may find papers where the person is mentioned, rather than papers they authored.Use a comma to separate multiple people: J Smith, RL Jones, Macarthur.Use these formats for best results: Smith or J Smith.For best results, use the separate Authors field to search for author names.Use quotation marks " " around specific phrases where you want the entire phrase only.Question mark (?) - Example: "gr?y" retrieves documents containing "grey" or "gray".Asterisk ( * ) - Example: "elect*" retrieves documents containing "electron," "electronic," and "electricity".Improve efficiency in your search by using wildcards.Example: (photons AND downconversion) - pump.Example: (diode OR solid-state) AND laser.Note the Boolean sign must be in upper-case. Separate search groups with parentheses and Booleans.Keep it simple - don't use too many different parameters.
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