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Urban shader using Quadtree Displacement Mapping

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This commit is contained in:
Frederic Bouvier 2010-10-25 22:37:05 +02:00
parent ab320e4c73
commit a3813bda8d
2 changed files with 114 additions and 33 deletions
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31
Effects/urban.eff
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@ -7,6 +7,7 @@
<depth-factor type="float">0.008</depth-factor> <depth-factor type="float">0.008</depth-factor>
<night-color type="vec3d">0.75 0.59 0.05</night-color> <night-color type="vec3d">0.75 0.59 0.05</night-color>
<quality-level><use>/sim/rendering/quality-level</use></quality-level> <quality-level><use>/sim/rendering/quality-level</use></quality-level>
<max-lod-level>10</max-lod-level>
</parameters> </parameters>
<generate> <generate>
<normal type="int">15</normal> <normal type="int">15</normal>
@ -68,12 +69,24 @@
<filter><use>texture[2]/filter</use></filter> <filter><use>texture[2]/filter</use></filter>
<wrap-s><use>texture[2]/wrap-s</use></wrap-s> <wrap-s><use>texture[2]/wrap-s</use></wrap-s>
<wrap-t><use>texture[2]/wrap-t</use></wrap-t> <wrap-t><use>texture[2]/wrap-t</use></wrap-t>
<internal-format> <internal-format><use>texture[2]/internal-format</use></internal-format>
<use>texture[2]/internal-format</use>
</internal-format>
</texture-unit> </texture-unit>
<texture-unit> <texture-unit>
<unit>2</unit> <unit>2</unit>
<image><use>texture[2]/image</use></image>
<filter>nearest-mipmap-nearest</filter>
<wrap-s><use>texture[2]/wrap-s</use></wrap-s>
<wrap-t><use>texture[2]/wrap-t</use></wrap-t>
<internal-format><use>texture[2]/internal-format</use></internal-format>
<mipmap-control>
<function-r>average</function-r>
<function-g>average</function-g>
<function-b>average</function-b>
<function-a>min</function-a>
</mipmap-control>
</texture-unit>
<texture-unit>
<unit>3</unit>
<type>noise</type> <type>noise</type>
</texture-unit> </texture-unit>
<program> <program>
@ -102,10 +115,15 @@
<type>sampler-2d</type> <type>sampler-2d</type>
<value type="int">1</value> <value type="int">1</value>
</uniform> </uniform>
<uniform>
<name>QDMTex</name>
<type>sampler-2d</type>
<value type="int">2</value>
</uniform>
<uniform> <uniform>
<name>NoiseTex</name> <name>NoiseTex</name>
<type>sampler-3d</type> <type>sampler-3d</type>
<value type="int">2</value> <value type="int">3</value>
</uniform> </uniform>
<uniform> <uniform>
<name>depth_factor</name> <name>depth_factor</name>
@ -132,6 +150,11 @@
<type>float</type> <type>float</type>
<value><use>snow-level</use></value> <value><use>snow-level</use></value>
</uniform> </uniform>
<uniform>
<name>max_lod_level</name>
<type>float</type>
<value><use>max-lod-level</use></value>
</uniform>
</pass> </pass>
</technique> </technique>
</PropertyList> </PropertyList>

116
Shaders/urban.frag
View file

@ -2,9 +2,15 @@
// Licence: GPL v2 // Licence: GPL v2
// Author: Frederic Bouvier. // Author: Frederic Bouvier.
// Adapted from the paper by F. Policarpo et al. : Real-time Relief Mapping on Arbitrary Polygonal Surfaces // Adapted from the paper by F. Policarpo et al. : Real-time Relief Mapping on Arbitrary Polygonal Surfaces
// Adapted from the paper and sources by M. Drobot in GPU Pro : Quadtree Displacement Mapping with Height Blending
#version 120 #version 120
#define TEXTURE_MIP_LEVELS 10
#define TEXTURE_PIX_COUNT 1024 //pow(2,TEXTURE_MIP_LEVELS)
#define BINARY_SEARCH_COUNT 10
#define BILINEAR_SMOOTH_FACTOR 2.0
varying vec4 rawpos; varying vec4 rawpos;
varying vec4 ecPosition; varying vec4 ecPosition;
varying vec3 VNormal; varying vec3 VNormal;
@ -16,6 +22,7 @@ varying vec4 constantColor;
uniform sampler3D NoiseTex; uniform sampler3D NoiseTex;
uniform sampler2D BaseTex; uniform sampler2D BaseTex;
uniform sampler2D NormalTex; uniform sampler2D NormalTex;
uniform sampler2D QDMTex;
uniform float depth_factor; uniform float depth_factor;
uniform float tile_size; uniform float tile_size;
uniform float quality_level; // From /sim/rendering/quality-level uniform float quality_level; // From /sim/rendering/quality-level
@ -23,52 +30,103 @@ uniform float snowlevel; // From /sim/rendering/snow-level-m
uniform vec3 night_color; uniform vec3 night_color;
const float scale = 1.0; const float scale = 1.0;
int linear_search_steps = 10; int GlobalIterationCount = 0;
int gIterationCap = 64;
float ray_intersect(sampler2D reliefMap, vec2 dp, vec2 ds) void QDM(inout vec3 p, inout vec3 v)
{ {
float size = 1.0 / float(linear_search_steps); const int MAX_LEVEL = TEXTURE_MIP_LEVELS;
float depth = 0.0; const float NODE_COUNT = TEXTURE_PIX_COUNT;
float best_depth = 1.0; const float TEXEL_SPAN_HALF = 1.0 / NODE_COUNT / 2.0;
for(int i = 0; i < linear_search_steps - 1; ++i) float fDeltaNC = TEXEL_SPAN_HALF * depth_factor;
vec3 p2 = p;
float level = MAX_LEVEL;
vec2 dirSign = (sign(v.xy) + 1.0) * 0.5;
GlobalIterationCount = 0;
float d = 0;
while (level >= 0 && GlobalIterationCount < gIterationCap)
{ {
depth += size; vec4 uv = vec4(p2.xyz, level);
float t = step(0.95, texture2D(reliefMap, dp + ds * depth).a); d = texture2DLod(QDMTex, uv.xy, uv.w).w;
if(best_depth > 0.996)
if(depth >= t)
best_depth = depth;
}
depth = best_depth;
const int binary_search_steps = 5; if (d > p2.z)
for(int i = 0; i < binary_search_steps; ++i)
{
size *= 0.5;
float t = step(0.95, texture2D(reliefMap, dp + ds * depth).a);
if(depth >= t)
{ {
best_depth = depth; //predictive point of ray traversal
depth -= 2.0 * size; vec3 tmpP2 = p + v * d;
//current node count
float nodeCount = pow(2.0, (MAX_LEVEL - level));
//current and predictive node ID
vec4 nodeID = floor(vec4(p2.xy, tmpP2.xy)*nodeCount);
//check if we are crossing the current cell
if (nodeID.x != nodeID.z || nodeID.y != nodeID.w)
{
//calculate distance to nearest bound
vec2 a = p2.xy - p.xy;
vec2 p3 = (nodeID.xy + dirSign) / nodeCount;
vec2 b = p3.xy - p.xy;
vec2 dNC = (b.xy * p2.z) / a.xy;
//take the nearest cell
d = min(d,min(dNC.x, dNC.y))+fDeltaNC;
level++;
//use additional convergence speed-up
#ifdef USE_QDM_ASCEND_INTERVAL
if(frac(level*0.5) > EPSILON)
level++;
#elseif USE_QDM_ASCEND_CONST
level++;
#endif
}
p2 = p + v * d;
} }
depth += size; level--;
GlobalIterationCount++;
} }
return(best_depth); //
// Manual Bilinear filtering
//
float rayLength = length(p2.xy - p.xy) + fDeltaNC;
float dA = p2.z * (rayLength - BILINEAR_SMOOTH_FACTOR * TEXEL_SPAN_HALF) / rayLength;
float dB = p2.z * (rayLength + BILINEAR_SMOOTH_FACTOR * TEXEL_SPAN_HALF) / rayLength;
vec4 p2a = vec4(p + v * dA, 0);
vec4 p2b = vec4(p + v * dB, 0);
dA = texture2DLod(NormalTex, p2a.xy, p2a.w).w;
dB = texture2DLod(NormalTex, p2b.xy, p2b.w).w;
dA = abs(p2a.z - dA);
dB = abs(p2b.z - dB);
p2 = mix(p2a.xyz, p2b.xyz, dA / (dA + dB));
p = p2;
}
float ray_intersect(vec2 dp, vec2 ds)
{
vec3 p = vec3( dp, 0.0 );
vec3 v = vec3( ds, 1.0 );
QDM( p, v );
return p.z;
} }
void main (void) void main (void)
{ {
if ( quality_level >= 3.5 ) {
linear_search_steps = 20;
}
vec3 ecPos3 = ecPosition.xyz / ecPosition.w; vec3 ecPos3 = ecPosition.xyz / ecPosition.w;
vec3 V = normalize(ecPos3); vec3 V = normalize(ecPos3);
vec3 s = vec3(dot(V, VTangent), dot(V, VBinormal), dot(VNormal, -V)); vec3 s = vec3(dot(V, VTangent), dot(V, VBinormal), dot(VNormal, -V));
vec2 ds = s.xy * depth_factor / s.z; vec2 ds = s.xy * depth_factor / s.z;
vec2 dp = gl_TexCoord[0].st - ds; vec2 dp = gl_TexCoord[0].st - ds;
float d = ray_intersect(NormalTex, dp, ds); float d = ray_intersect(dp, ds);
vec2 uv = dp + ds * d; vec2 uv = dp + ds * d;
vec3 N = texture2D(NormalTex, uv).xyz * 2.0 - 1.0; vec3 N = texture2D(NormalTex, uv).xyz * 2.0 - 1.0;
@ -89,7 +147,7 @@ void main (void)
vec3 sl = normalize( vec3( dot( l, VTangent ), dot( l, VBinormal ), dot( -l, VNormal ) ) ); vec3 sl = normalize( vec3( dot( l, VTangent ), dot( l, VBinormal ), dot( -l, VNormal ) ) );
ds = sl.xy * depth_factor / sl.z; ds = sl.xy * depth_factor / sl.z;
dp -= ds * d; dp -= ds * d;
float dl = ray_intersect(NormalTex, dp, ds); float dl = ray_intersect(dp, ds);
if ( dl < d - 0.05 ) if ( dl < d - 0.05 )
shadow_factor = dot( constantColor.xyz, vec3( 1.0, 1.0, 1.0 ) ) * 0.25; shadow_factor = dot( constantColor.xyz, vec3( 1.0, 1.0, 1.0 ) ) * 0.25;
} }