-
sparker
thiago
Manta Interactive Ray Tracer Development Mailing List
Text archives Help
- From: knolla@sci.utah.edu
- To: manta@sci.utah.edu
- Subject: [MANTA] r1134 - in trunk: Model/Intersections Model/Primitives scenes
- Date: Sun, 2 Jul 2006 16:48:14 -0600 (MDT)
Author: knolla
Date: Sun Jul 2 16:48:13 2006
New Revision: 1134
Modified:
trunk/Model/Intersections/IsosurfaceImplicit.cc
trunk/Model/Intersections/IsosurfaceImplicit.h
trunk/Model/Primitives/IsosurfaceGridVolume.cc
trunk/Model/Primitives/IsosurfaceOctreeVolume.cc
trunk/scenes/gridisovol.cc
trunk/scenes/octisovol.cc
Log:
Implemented Neubauer intersection for single-rayisosurfacing; more stable and
faster results. Also fixed default lighting for octree and grid isovolume
scenes.
Modified: trunk/Model/Intersections/IsosurfaceImplicit.cc
==============================================================================
--- trunk/Model/Intersections/IsosurfaceImplicit.cc (original)
+++ trunk/Model/Intersections/IsosurfaceImplicit.cc Sun Jul 2 16:48:13
2006
@@ -6,8 +6,10 @@
using namespace Manta;
using namespace std;
+#define NEUBAUER_ITERATIONS 3
+
//From Steven Parker's 1997 RTRT isosurface intersection
-bool IsosurfaceImplicit::single_intersect(const Vector& orig, const Vector&
dir,
+bool IsosurfaceImplicit::single_intersect_schwarze(const Vector& orig, const
Vector& dir,
const Vector& pmin, const Vector& pmax, float
rho[2][2][2],
float iso, float tmin, float tmax, float& t)
{
@@ -71,6 +73,55 @@
}
+
+bool IsosurfaceImplicit::single_intersect_neubauer(const Vector& orig, const
Vector& dir,
+ const Vector& pmin, const Vector& pmax, float
rho[2][2][2],
+ float iso, float tenter, float texit, float& hit_t)
+{
+ const Vector p0 = (orig + dir*tenter) - pmin;
+ const Vector p1 = (orig + dir*texit) - pmin;
+
+ CubicPoly poly;
+ poly.generate(p0, p1, rho, iso);
+
+ float t0 = 0.f;
+ float t1 = 1.f;
+ float D0 = poly.d;
+ float D1 = poly.a+poly.b+poly.c+poly.d;
+
+ if (D0 * D1 >= 0)
+ return false;
+
+ #pragma unroll(NEUBAUER_ITERATIONS)
+ for (int i=0;i<NEUBAUER_ITERATIONS;i++)
+ {
+ //compute linear interpolation
+ const float denom = 1./(D0 - D1);
+ float t = t0 + D0*denom*(t1-t0);
+
+ //re-evaluate
+ float D = poly.eval(t);
+
+ if (D0*D < 0)
+ {
+ t1 = t;
+ D1 = D;
+ }
+ else
+ {
+ t0 = t;
+ D0 = D;
+ }
+ }
+
+ const float denom = 1./(D0-D1);
+ const float t = t0 + D0*denom*(t1-t0);
+ hit_t = tenter + t*(texit-tenter);
+
+ return (hit_t < texit);
+}
+
+
//From Steven Parker's 1997 RTRT isosurface intersection
void IsosurfaceImplicit::single_normal(Vector& outNormal, const Vector&
pmin, const Vector& pmax, const Vector& p, float rho[2][2][2])
{
@@ -165,7 +216,6 @@
if (int_thisvoxelmask == 0) //if none of them hit, don't bother
iterating any more
continue;
- #define NEUBAUER_ITERATIONS 3
#pragma unroll(NEUBAUER_ITERATIONS)
for (int i=0;i<NEUBAUER_ITERATIONS;i++)
{
Modified: trunk/Model/Intersections/IsosurfaceImplicit.h
==============================================================================
--- trunk/Model/Intersections/IsosurfaceImplicit.h (original)
+++ trunk/Model/Intersections/IsosurfaceImplicit.h Sun Jul 2 16:48:13
2006
@@ -17,14 +17,111 @@
{
struct IsosurfaceImplicit
{
- static bool single_intersect(const Vector& orig, const Vector& dir,
+
+ static bool single_intersect_schwarze(const Vector& orig, const
Vector& dir,
const Vector& pmin, const Vector& pmax, float
rho[2][2][2],
float iso, float tmin, float tmax, float& t);
+ static bool single_intersect_neubauer(const Vector& orig, const
Vector& dir,
+ const Vector& pmin, const Vector& pmax, float rho[2][2][2],
+ float iso, float tenter, float texit, float& hit_t);
+
static void single_normal(Vector& outNormal, const Vector& pmin,
const Vector& pmax, const Vector& p, float
rho[2][2][2]);
+
//TODO - non-SSE packet intersection
+
+ //From Marmitt, Wald et al. 04 - for Neubauer intersection
+ struct CubicPoly
+ {
+ float a,b,c,d;
+
+ void generate(const Vector& p0,
+ const Vector& p1,
+ const float voxel[2][2][2],
+ const float isovalue)
+ {
+ const Vector e0 = Vector(1,1,1) - p0;
+ const Vector e1 = p0;
+ const Vector d1 = p1 - p0;
+ float interimROO = d1[1] * d1[2];
+
+ const float interimRRR = d1[0] * interimROO;
+ const float interimNRR = e1[0] * interimROO;
+ const float interimORR = e0[0] * interimROO;
+ interimROO = e1[1] * d1[2];
+ const float interimRNR = d1[0] * interimROO;
+ const float interimNNR = e1[0] * interimROO;
+ const float interimONR = e0[0] * interimROO;
+ interimROO = d1[1] * e1[2];
+ const float interimRRN = d1[0] * interimROO;
+ const float interimNRN = e1[0] * interimROO;
+ const float interimORN = e0[0] * interimROO;
+ interimROO = d1[1] * e0[2];
+ const float interimRRO = d1[0] * interimROO;
+ const float interimNRO = e1[0] * interimROO;
+ const float interimORO = e0[0] * interimROO;
+ interimROO = e0[1] * d1[2];
+ const float interimROR = d1[0] * interimROO;
+ const float interimNOR = e1[0] * interimROO;
+ const float interimOOR = e0[0] * interimROO;
+ interimROO = d1[0] * e1[1];
+ const float interimRNN = interimROO * e1[2];
+ const float interimRNO = interimROO * e0[2];
+ interimROO = d1[0] * e0[1];
+ const float interimRON = interimROO * e1[2];
+ interimROO = interimROO * e0[2];
+
+ a
+ = interimRRR * ( voxel[1][1][1]
+ - voxel[1][1][0]
+ - voxel[1][0][1]
+ + voxel[1][0][0]
+ - voxel[0][1][1]
+ + voxel[0][1][0]
+ + voxel[0][0][1]
+ - voxel[0][0][0]);
+ b
+ = voxel[1][1][1] * (interimNRR + interimRNR + interimRRN)
+ - voxel[1][1][0] * (interimNRR + interimRNR - interimRRO)
+ - voxel[1][0][1] * (interimNRR - interimROR + interimRRN)
+ + voxel[1][0][0] * (interimNRR - interimROR - interimRRO)
+ + voxel[0][1][1] * (interimORR - interimRNR - interimRRN)
+ - voxel[0][1][0] * (interimORR - interimRNR + interimRRO)
+ - voxel[0][0][1] * (interimORR + interimROR - interimRRN)
+ + voxel[0][0][0] * (interimORR + interimROR + interimRRO);
+
+ c
+ = voxel[1][1][1] * (interimRNN + interimNRN + interimNNR)
+ + voxel[1][1][0] * (interimRNO + interimNRO - interimNNR)
+ + voxel[1][0][1] * (interimRON - interimNRN + interimNOR)
+ + voxel[1][0][0] * (interimROO - interimNRO - interimNOR)
+ + voxel[0][1][1] * (interimORN + interimONR - interimRNN)
+ - voxel[0][1][0] * (interimRNO - interimORO + interimONR)
+ - voxel[0][0][1] * (interimRON + interimORN - interimOOR)
+ - voxel[0][0][0] * (interimROO + interimORO + interimOOR);
+
+ d
+ =
+ e1[0] * (e1[1] * (e1[2] * voxel[1][1][1] +
+ e0[2] * voxel[1][1][0]) +
+ e0[1] * (e1[2] * voxel[1][0][1] +
+ e0[2] * voxel[1][0][0])) +
+ e0[0] * (e1[1] * (e1[2] * voxel[0][1][1] +
+ e0[2] * voxel[0][1][0]) +
+ e0[1] * (e1[2] * voxel[0][0][1] +
+ e0[2] * voxel[0][0][0]));
+
+ d -= isovalue;
+ }
+
+ inline float eval(const float t) const
+ {
+ return ((((a)*t+b)*t+c)*t+d);
+ }
+ };
+
#ifdef MANTA_SSE
static void sse_intersect(SSERayPacket& srp,
@@ -35,7 +132,7 @@
static void sse_normal(SSERayPacket& srp, int smd,
sse_t normal[], const Vector& pmin, const Vector& pmax,
const float rho[2][2][2]);
-
+
struct CubicPoly4
{
MANTA_ALIGN(16) sse_t a, b, c, d;
Modified: trunk/Model/Primitives/IsosurfaceGridVolume.cc
==============================================================================
--- trunk/Model/Primitives/IsosurfaceGridVolume.cc (original)
+++ trunk/Model/Primitives/IsosurfaceGridVolume.cc Sun Jul 2 16:48:13
2006
@@ -457,7 +457,7 @@
rho[1][1][0]=rhos[6];
rho[1][1][1]=rhos[7];
- if (IsosurfaceImplicit::single_intersect(orig, dir, p0,
p1, rho,
+ if (IsosurfaceImplicit::single_intersect_neubauer(orig,
dir, p0, p1, rho,
isoval, t, tmax, hit_t))
{
if (rays.hit(which_one, hit_t,
PrimitiveCommon::getMaterial(), this, 0))
Modified: trunk/Model/Primitives/IsosurfaceOctreeVolume.cc
==============================================================================
--- trunk/Model/Primitives/IsosurfaceOctreeVolume.cc (original)
+++ trunk/Model/Primitives/IsosurfaceOctreeVolume.cc Sun Jul 2 16:48:13
2006
@@ -557,7 +557,7 @@
if (octdata->get_isovalue() >= min_rho &&
octdata->get_isovalue() <= max_rho)
{
float hit_t;
- if (IsosurfaceImplicit::single_intersect(orig, dir,
cmin, cmax, rho,
+ if (IsosurfaceImplicit::single_intersect_neubauer(orig,
dir, cmin, cmax, rho,
octdata->get_isovalue(), child_tenter, child_texit,
hit_t))
{
if (rays.hit(which_one, hit_t,
PrimitiveCommon::getMaterial(), this, 0))
@@ -709,7 +709,7 @@
if (octdata->get_isovalue() >= min_rho && octdata->get_isovalue() <=
max_rho)
{
float hit_t;
- if (IsosurfaceImplicit::single_intersect(orig, dir, cmin, cmax,
rho,
+ if (IsosurfaceImplicit::single_intersect_neubauer(orig, dir,
cmin, cmax, rho,
octdata->get_isovalue(), child_tenter, child_texit, hit_t))
{
if (rays.hit(which_one, hit_t,
PrimitiveCommon::getMaterial(), this, 0))
Modified: trunk/scenes/gridisovol.cc
==============================================================================
--- trunk/scenes/gridisovol.cc (original)
+++ trunk/scenes/gridisovol.cc Sun Jul 2 16:48:13 2006
@@ -95,15 +95,16 @@
PinholeCamera *camera = new PinholeCamera(eye, lookat, up, fov);
//scene->setCamera(camera);
+ //NOTE: this will create a light directly "above" the volume in the +up
direction.
+ // Some volumes (e.g. heptane) will require us to change this to a -
LightSet *lights = new LightSet();
- lights->add( new PointLight(Vector(eye + 25.f*(up + Cross(eye-lookat,
up))), Color(RGBColor(1,1,1))) );
+ lights->add( new PointLight( Vector(lookat + (10.f * lookat.length()) *
up ), Color(RGBColor(1,1,1)) ) );
lights->setAmbientLight( new ConstantAmbient(
Color(RGBColor(0.4,0.5,0.5) ) ));
scene->setLights(lights);
// Background.
- scene->setBackground( new ConstantBackground( Color(RGB(0.0, 0.0, 0.0))
) );
- //scene->setBackground( new ConstantBackground( Color(RGB(0.99, 0.98,
0.98)) ) );
+ scene->setBackground( new ConstantBackground( Color(RGB(.96, 0.96,
0.97)) ) );
return scene;
}
Modified: trunk/scenes/octisovol.cc
==============================================================================
--- trunk/scenes/octisovol.cc (original)
+++ trunk/scenes/octisovol.cc Sun Jul 2 16:48:13 2006
@@ -152,14 +152,16 @@
PinholeCamera *camera = new PinholeCamera(eye, lookat, up, fov);
//scene->setCamera(camera);
+ //NOTE: this will create a light directly "above" the volume in the +up
direction.
+ // Some volumes (e.g. heptane) will require us to change this to a -
LightSet *lights = new LightSet();
- lights->add( new PointLight(Vector(eye + 25.f*(up + Cross(eye-lookat,
up))), Color(RGBColor(1,1,1))) );
+ lights->add( new PointLight( Vector(lookat + (10.f * lookat.length()) *
up ), Color(RGBColor(1,1,1)) ) );
lights->setAmbientLight( new ConstantAmbient(
Color(RGBColor(0.4,0.5,0.5) ) ));
scene->setLights(lights);
// Background.
- scene->setBackground( new ConstantBackground( Color(RGB(0.0, 0.0, 0.0))
) );
+ scene->setBackground( new ConstantBackground( Color(RGB(.96, 0.96,
0.97)) ) );
return scene;
}
- [MANTA] r1134 - in trunk: Model/Intersections Model/Primitives scenes, knolla, 07/02/2006
Archive powered by MHonArc 2.6.16.
