video<\/a>.<\/p>\n <\/p>\n
Parallax Occlusion Mapping GLSL shader<\/p>\n
\/*
\nmost of credits to Igor Dykhta
\nlighting and vertex rewrited by GIO
\n*\/<\/p>\n
[vertex]<\/p>\n
#version 150
\nprecision highp float;<\/p>\n
in vec4 v_position;
\nin vec3 v_normal;
\nin vec2 v_texCoord;
\nin vec3 v_tangent;<\/p>\n
\/\/ uniforms
\nuniform mat4 u_model_mat;
\nuniform mat4 u_view_mat;
\nuniform mat4 u_proj_mat;
\nuniform mat3 u_normal_mat;
\nuniform vec3 u_light_position;
\nuniform vec3 u_camera_position;<\/p>\n
\/\/ data for fragment shader
\nout vec2 o_texcoords;
\nout vec3 o_toLightInTangentSpace;
\nout vec3 o_toCameraInTangentSpace;<\/p>\n
void main(void)
\n{
\no_texcoords = v_texCoord;<\/p>\n
vec3 n = normalize (u_normal_mat * v_normal);
\nvec3 t = normalize (u_normal_mat * v_tangent);
\nvec3 b = cross (n, t);<\/p>\n
mat3 tbnMatrix = mat3(t.x, b.x, n.x,
\nt.y, b.y, n.y,
\nt.z, b.z, n.z);<\/p>\n
mat4 modelViewMatrix = u_view_mat * u_model_mat;
\nmat4 mvpMatrix = u_proj_mat * modelViewMatrix;
\nvec4 worldPosition = vec4(v_position.x, v_position.y, v_position.z, 1.0);<\/p>\n
gl_Position = mvpMatrix * worldPosition;
\nworldPosition = modelViewMatrix * worldPosition;<\/p>\n
o_toCameraInTangentSpace = -(worldPosition.xyz \/ worldPosition.w);
\no_toCameraInTangentSpace = normalize(tbnMatrix * o_toCameraInTangentSpace);<\/p>\n
o_toLightInTangentSpace = (u_light_position – worldPosition.xyz); \/\/u_light_position = position * viewmatrix
\no_toLightInTangentSpace = normalize(tbnMatrix * o_toLightInTangentSpace);
\n}<\/p>\n
[fragment]<\/p>\n
#version 150
\nprecision highp float;<\/p>\n
\/\/ data from vertex shader
\nin vec2 o_texcoords;
\nin vec3 o_toLightInTangentSpace;
\nin vec3 o_toCameraInTangentSpace;<\/p>\n
\/\/ textures
\nuniform sampler2D u_diffuseTexture;
\nuniform sampler2D u_heightTexture;
\nuniform sampler2D u_normalTexture;
\nuniform float useGloss;
\nuniform sampler2D u_GlossTexture;<\/p>\n
\/\/ scale for size of Parallax Mapping effect
\nuniform float u_parallaxScale; \/\/ ~0.1<\/p>\n
uniform vec4 lightDiffuse;
\nuniform vec4 matDiffuse;
\nuniform vec4 lightAmbient;
\nuniform vec4 matAmbient;
\nuniform vec4 lightSpecular;
\nuniform vec4 matSpecular;
\nuniform float matShininess;
\nuniform float lightAttenuation;<\/p>\n
out vec4 fragColor;<\/p>\n
\/\/——————————————————————–
\n\/\/ PARALLAX OCCLUSION (POM)
\n\/\/——————————————————————–<\/p>\n
vec2 parallaxMapping(in vec3 V, in vec2 T, out float parallaxHeight)
\n{<\/p>\n
float u_adaptiveScale = 0.5; \/\/declarations for tests
\nfloat u_minNumberOfLayers = 40.0;
\nfloat u_maxNumberOfLayers = 200.0;<\/p>\n
\/\/ multiplier for offsets of texture coordinates, determines amount of paralax
\nfloat parallaxScale = u_parallaxScale * (1.0 – u_adaptiveScale);
\nfloat parallaxAdaptive = u_parallaxScale * pow(abs(dot(vec3(0, 0, 1), V)), 0.5) * u_adaptiveScale;<\/p>\n
\/\/ number of layer to check. Depends on view angle
\nfloat numLayers = floor(mix(u_maxNumberOfLayers, u_minNumberOfLayers, abs(dot(vec3(0.0, 0.0, 1.0), V))));<\/p>\n
\/\/ height of current layer
\nfloat currentLayerHeight = 0.0;
\n\/\/ height of each layer
\nfloat layerHeight = 1.0 \/ numLayers;
\n\/\/ change of texture coordinates with each layer
\nvec2 texStep = (parallaxScale ) * V.xy \/ V.z \/ numLayers;<\/p>\n
\/\/ initial texcoords
\nvec2 currentTextureCoords = T;
\n\/\/ get first height from height map
\nfloat heightFromTexture = 1.0 – texture(u_heightTexture, currentTextureCoords).r;<\/p>\n
\/\/ while ray is above surface
\nwhile (heightFromTexture > currentLayerHeight)
\n{
\n\/\/ update height with height of next level
\ncurrentLayerHeight += layerHeight;
\n\/\/ offset texture coordinates for sampling
\ncurrentTextureCoords -= texStep;
\n\/\/ get new height from height map
\nheightFromTexture = 1.0 – texture(u_heightTexture, currentTextureCoords).r;
\n}<\/p>\n
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/<\/p>\n
\/\/ previous texture coordinates
\nvec2 prevTexCoords = currentTextureCoords + texStep;<\/p>\n
\/\/ heights
\nfloat nextHeight = heightFromTexture – currentLayerHeight;
\nfloat previousHeight = texture(u_heightTexture, prevTexCoords).r – currentLayerHeight + layerHeight;<\/p>\n
\/\/ interpolation weight
\nfloat weight = nextHeight \/ (nextHeight – previousHeight);<\/p>\n
\/\/ interpolate to get texture coordinates
\nvec2 interpolatedTexCoords = prevTexCoords * weight + currentTextureCoords * (1.0 – weight);<\/p>\n
\/\/ output height of last fragment
\nparallaxHeight = currentLayerHeight + previousHeight * weight + nextHeight * (1.0 – weight);<\/p>\n
\/\/ save final texture coordinates offset
\nreturn interpolatedTexCoords;<\/p>\n
}<\/p>\n
\/\/——————————————————————–
\n\/\/ Implements self-shadowing technique – hard or soft shadows Returns shadow factor
\nfloat parallaxSoftShadowMultiplier(in vec3 L, in vec2 initialTexCoord, in float initialHeight)
\n{<\/p>\n
float shadowMultiplier = 1.0;
\nconst float minLayers = 15.0;
\nconst float maxLayers = 30.0;<\/p>\n
\/\/ calculate lighting only for surface oriented to the light source
\nif(dot(vec3(0.0, 0.0, 1.0), L) > 0.0)
\n{<\/p>\n
\/\/ calculate initial parameters
\nfloat numSamplesUnderSurface = 0.0;
\nshadowMultiplier = 0.0;
\nfloat numLayers = mix(maxLayers, minLayers, abs(dot(vec3(0.0, 0.0, 1.0), L)));
\nfloat layerHeight = initialHeight \/ numLayers;
\nvec2 texStep = u_parallaxScale * L.xy \/ L.z \/ numLayers;<\/p>\n
\/\/ current parameters
\nfloat currentLayerHeight = initialHeight – layerHeight;
\nvec2 currentTextureCoords = initialTexCoord + texStep;
\nfloat heightFromTexture = texture(u_heightTexture, currentTextureCoords).r;
\nfloat stepIndex = 1.0; \/\/era int<\/p>\n
\/\/ while point is below depth 0.0 )
\nwhile (currentLayerHeight > 0.0)
\n{
\n\/\/ if point is under the surface
\nif (heightFromTexture < currentLayerHeight)
\n{
\n\/\/ calculate partial shadowing factor
\nnumSamplesUnderSurface += 1.0;
\nfloat newShadowMultiplier = (currentLayerHeight – heightFromTexture) *
\n(1.0 – stepIndex \/ numLayers);
\nshadowMultiplier = max(shadowMultiplier, newShadowMultiplier);
\n}<\/p>\n
\/\/ offset to the next layer
\nstepIndex += 1.0;
\ncurrentLayerHeight -= layerHeight;
\ncurrentTextureCoords += texStep;
\nheightFromTexture = 1.0 – texture(u_heightTexture, currentTextureCoords).r;
\n}<\/p>\n
\/\/ Shadowing factor should be 1 if there were no points under the surface
\nif (numSamplesUnderSurface < 1.0)
\nshadowMultiplier = 1.0;
\nelse
\nshadowMultiplier = 1.0 – shadowMultiplier;
\n}
\nreturn shadowMultiplier;<\/p>\n
}
\n\/\/——————————————————————–
\n\/\/ Calculates lighting by Blinn-Phong model and Normal Mapping – heavily modded by Gio
\nvec4 normalMappingLighting(in vec2 T, in vec3 L, in vec3 V, float shadowMultiplier)
\n{<\/p>\n
vec3 N = normalize(texture(u_normalTexture, T).xyz * 2.0 – 1.0);
\nvec4 D = texture(u_diffuseTexture, T);<\/p>\n
\/\/attenuation
\nfloat dist = length(L);
\nfloat coeff = dist * lightAttenuation;
\nvec4 attenuation = vec4(coeff,coeff,coeff,1.0);<\/p>\n
\/\/ambient
\nvec4 ambient = (lightAmbient + matAmbient) * attenuation;
\n\/\/ diffuse lighting
\nfloat diffPower = clamp(dot(N, L), 0, 1);
\nvec4 diffuse = (diffPower * (lightDiffuse + matDiffuse)) * attenuation;
\n\/\/ specular lighting
\nfloat specPower = 0;
\nvec4 specular = vec4(0,0,0,1);
\nif(dot(N, L) > 0.0)
\n{
\nvec3 R = reflect(-L, N);
\nspecPower = pow(max(0.0,dot(R,V)), matShininess);
\nspecular = (specPower * matSpecular) * attenuation;<\/p>\n
if (useGloss > 0.0)
\n{
\nfloat opacity = texture(u_GlossTexture, o_texcoords.st).r;
\nspecular = specular * opacity;
\n}
\n}<\/p>\n
vec4 resColor;
\nresColor = D * (ambient + (diffuse + specular) * pow(shadowMultiplier, 4));
\nreturn resColor;
\n}
\n\/\/——————————————————————–
\nvoid main(void)
\n{
\n\/\/ normalize vectors after vertex shader
\nvec3 V = normalize(o_toCameraInTangentSpace);
\nvec3 L = normalize(o_toLightInTangentSpace);<\/p>\n
\/\/ get new texture coordinates from Parallax Mapping
\nfloat parallaxHeight = 0;
\nvec2 T = parallaxMapping(V, o_texcoords, parallaxHeight);<\/p>\n
\/\/ get self-shadowing factor for elements of parallax
\nfloat shadowMultiplier = parallaxSoftShadowMultiplier(L, T, parallaxHeight – 0.05);<\/p>\n
\/\/ calculate lighting
\nfragColor = normalMappingLighting(T, L, V, shadowMultiplier);
\n}
\n\/\/——————————————————————–<\/p>\n
<\/p>\n
<\/p>\n
<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Engine C3, a total revamp of Chimera, is almost completed (assuming that an engine can be defined as completed …). C3 contains a lot of advanced features: it is completely shader-based and contains many postprocessing effects such as filmgrain, depth-of-field etc. but probably the best thing is that it runs on Windows (core 330), macOS […]<\/p>\n","protected":false},"author":1,"featured_media":1552,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[7,201,1,14,8],"tags":[163,37,165,166,167,164],"class_list":{"0":"post-1551","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-ios","8":"category-macos","9":"category-news","10":"category-osx","11":"category-windows","12":"tag-c3","13":"tag-chimera","14":"tag-normal-mapping","15":"tag-opengl-es-2","16":"tag-opengl-es-3","17":"tag-parallax-occlusion-ios","18":"czr-hentry"},"_links":{"self":[{"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/posts\/1551","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1551"}],"version-history":[{"count":28,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/posts\/1551\/revisions"}],"predecessor-version":[{"id":2345,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/posts\/1551\/revisions\/2345"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=\/wp\/v2\/media\/1552"}],"wp:attachment":[{"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1551"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1551"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.giodalnegro.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1551"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}