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Patch #8034: "soft" option for halos, which avoids ugly intersections

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with geometry, and makes halos look more volumetric.

Patch contributed by Markus Ilmola, thanks!
This commit is contained in:
Brecht Van Lommel
2008-04-14 19:48:14 +00:00
parent 7eb1b45281
commit 0b8b4369c9
5 changed files with 112 additions and 63 deletions
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88
source/blender/render/intern/source/pixelshading.c
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@@ -24,6 +24,7 @@
* ***** END GPL LICENSE BLOCK *****
*/
#include <float.h>
#include <math.h>
#include <string.h>
#include "BLI_arithb.h"
@@ -243,8 +244,36 @@ static void render_lighting_halo(HaloRen *har, float *colf)
}
/**
* Converts a halo z-buffer value to distance from the camera's near plane
* @param z The z-buffer value to convert
* @return a distance from the camera's near plane in blender units
*/
static float haloZtoDist(int z)
{
float zco = 0;
void shadeHaloFloat(HaloRen *har, float *col, int zz,
if(z >= 0x7FFFFF)
return 10e10;
else {
zco = (float)z/(float)0x7FFFFF;
if(R.r.mode & R_ORTHO)
return (R.winmat[3][2] - zco*R.winmat[3][3])/(R.winmat[2][2]);
else
return (R.winmat[3][2])/(R.winmat[2][2] - R.winmat[2][3]*zco);
}
}
/**
* @param col (float[4]) Store the rgb color here (with alpha)
* The alpha is used to blend the color to the background
* color_new = (1-alpha)*color_background + color
* @param zz The current zbuffer value at the place of this pixel
* @param dist Distance of the pixel from the center of the halo squared. Given in pixels
* @param xn The x coordinate of the pixel relaticve to the center of the halo. given in pixels
* @param yn The y coordinate of the pixel relaticve to the center of the halo. given in pixels
*/
int shadeHaloFloat(HaloRen *har, float *col, int zz,
float dist, float xn, float yn, short flarec)
{
/* fill in col */
@@ -263,12 +292,40 @@ void shadeHaloFloat(HaloRen *har, float *col, int zz,
}
else alpha= har->alfa;
if(alpha==0.0) {
col[0] = 0.0;
col[1] = 0.0;
col[2] = 0.0;
col[3] = 0.0;
return;
if(alpha==0.0)
return 0;
/* soften the halo if it intersects geometry */
if(har->mat->mode & MA_HALO_SOFT) {
float segment_length, halo_depth, distance_from_z, visible_depth, soften;
/* calculate halo depth */
segment_length= har->hasize*sasqrt(1.0f - dist/(har->rad*har->rad));
halo_depth= 2.0f*segment_length;
if(halo_depth < FLT_EPSILON)
return 0;
/* calculate how much of this depth is visible */
distance_from_z = haloZtoDist(zz) - haloZtoDist(har->zs);
visible_depth = halo_depth;
if(distance_from_z < segment_length) {
soften= (segment_length + distance_from_z)/halo_depth;
/* apply softening to alpha */
if(soften < 1.0f)
alpha *= soften;
if(alpha <= 0.0f)
return 0;
}
}
else {
/* not a soft halo. use the old softening code */
/* halo being intersected? */
if(har->zs> zz-har->zd) {
t= ((float)(zz-har->zs))/(float)har->zd;
alpha*= sqrt(sqrt(t));
}
}
radist= sqrt(dist);
@@ -366,21 +423,10 @@ void shadeHaloFloat(HaloRen *har, float *col, int zz,
if(ster<1.0) dist*= sqrt(ster);
}
}
/* halo being intersected? */
if(har->zs> zz-har->zd) {
t= ((float)(zz-har->zs))/(float)har->zd;
alpha*= sqrt(sqrt(t));
}
/* disputable optimize... (ton) */
if(dist<=0.00001) {
col[0] = 0.0;
col[1] = 0.0;
col[2] = 0.0;
col[3] = 0.0;
return;
}
if(dist<=0.00001)
return 0;
dist*= alpha;
ringf*= dist;
@@ -441,6 +487,8 @@ void shadeHaloFloat(HaloRen *har, float *col, int zz,
/* alpha requires clip, gives black dots */
if(col[3] > 1.0f)
col[3]= 1.0f;
return 1;
}
/* ------------------------------------------------------------------------- */