mirror of
https://github.com/TorqueGameEngines/Torque3D.git
synced 2026-03-06 14:00:39 +00:00
101 lines
3.3 KiB
GLSL
101 lines
3.3 KiB
GLSL
//-----------------------------------------------------------------------------
|
|
// Copyright (c) 2012 GarageGames, LLC
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to
|
|
// deal in the Software without restriction, including without limitation the
|
|
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
|
|
// sell copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in
|
|
// all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
// IN THE SOFTWARE.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
//
|
|
// A tip of the hat....
|
|
//
|
|
// The following wind effects were derived from the GPU Gems
|
|
// 3 chapter "Vegetation Procedural Animation and Shading in Crysis"
|
|
// by Tiago Sousa of Crytek.
|
|
//
|
|
|
|
vec4 smoothCurve( vec4 x )
|
|
{
|
|
return x * x * ( 3.0 - 2.0 * x );
|
|
}
|
|
|
|
vec4 triangleWave( vec4 x )
|
|
{
|
|
return abs( fract( x + 0.5 ) * 2.0 - 1.0 );
|
|
}
|
|
|
|
vec4 smoothTriangleWave( vec4 x )
|
|
{
|
|
return smoothCurve( triangleWave( x ) );
|
|
}
|
|
|
|
vec3 windTrunkBending( vec3 vPos, vec2 vWind, float fBendFactor )
|
|
{
|
|
// Smooth the bending factor and increase
|
|
// the near by height limit.
|
|
fBendFactor += 1.0;
|
|
fBendFactor *= fBendFactor;
|
|
fBendFactor = fBendFactor * fBendFactor - fBendFactor;
|
|
|
|
// Displace the vert.
|
|
vec3 vNewPos = vPos;
|
|
vNewPos.xy += vWind * fBendFactor;
|
|
|
|
// Limit the length which makes the bend more
|
|
// spherical and prevents stretching.
|
|
float fLength = length( vPos );
|
|
vPos = normalize( vNewPos ) * fLength;
|
|
|
|
return vPos;
|
|
}
|
|
|
|
vec3 windBranchBending( vec3 vPos,
|
|
vec3 vNormal,
|
|
|
|
float fTime,
|
|
float fWindSpeed,
|
|
|
|
float fBranchPhase,
|
|
float fBranchAmp,
|
|
float fBranchAtten,
|
|
|
|
float fDetailPhase,
|
|
float fDetailAmp,
|
|
float fDetailFreq,
|
|
|
|
float fEdgeAtten )
|
|
{
|
|
float fVertPhase = dot( vPos, vec3( fDetailPhase + fBranchPhase ) );
|
|
|
|
vec2 vWavesIn = fTime + vec2( fVertPhase, fBranchPhase );
|
|
|
|
vec4 vWaves = ( fract( vWavesIn.xxyy *
|
|
vec4( 1.975, 0.793, 0.375, 0.193 ) ) *
|
|
2.0 - 1.0 ) * fWindSpeed * fDetailFreq;
|
|
|
|
vWaves = smoothTriangleWave( vWaves );
|
|
|
|
vec2 vWavesSum = vWaves.xz + vWaves.yw;
|
|
|
|
// We want the branches to bend both up and down.
|
|
vWavesSum.y = 1.0 - ( vWavesSum.y * 2.0 );
|
|
|
|
vPos += vWavesSum.xxy * vec3( fEdgeAtten * fDetailAmp * vNormal.xy,
|
|
fBranchAtten * fBranchAmp );
|
|
|
|
return vPos;
|
|
}
|