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Re: OpenGL lighting fixes
|
From: |
Kai Habel |
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Subject: |
Re: OpenGL lighting fixes |
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Date: |
Wed, 04 Feb 2009 18:28:55 +0100 |
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User-agent: |
Thunderbird 2.0.0.19 (X11/20081227) |
Michael Goffioul schrieb:
> ...
>
>
>> 2.) The surface normals should be calculated when facelighting is set to
>> 'flat' too.
>>
>
> That's not my understanding of Matlab documentation. When facelighting
> is flat, the ligthening should be uniform across the each quad and equal
> to the lightening of the first vertex. That's why I don't update the normal on
> the usbsequent vertices.
>
>
> ...
Thanks,
for the reply and brief explanation. I did some tests myself, and can
confirm the behavior you have described above. So, I have reworked the
patch that only the calculation of diffuse reflection and surface
normals is modified.
Kai
# HG changeset patch
# User Kai Habel
# Date 1233761149 -3600
# Node ID 7d5d6dec3f4ffa16b50ee4d0087ca7e6c17fc32d
# Parent 98fb4f837962c70e0b7f357fc17914f87d110cf5
Fix calculation of diffuse reflectance. Calculate surface normals here now.
diff -r 98fb4f837962 -r 7d5d6dec3f4f src/ChangeLog
--- a/src/ChangeLog Fri Jan 30 18:38:44 2009 +0100
+++ b/src/ChangeLog Wed Feb 04 16:25:49 2009 +0100
@@ -1,3 +1,9 @@
+2009-02-02 Kai Habel <address@hidden>
+ * gl-render.cc (opengl_renderer::draw(surface::properties)): Normalize
+ surface normals. Correct calculation of diffuse lighting.
+ * gl-render.cc (opengl_renderer::draw(patch::properties)): Correct
+ calculation of diffuse lighting.
+
2009-01-29 John W. Eaton <address@hidden>
* pt-stmt.cc (tree_statement::eval): Check
diff -r 98fb4f837962 -r 7d5d6dec3f4f src/gl-render.cc
--- a/src/gl-render.cc Fri Jan 30 18:38:44 2009 +0100
+++ b/src/gl-render.cc Wed Feb 04 16:25:49 2009 +0100
@@ -1742,7 +1742,8 @@
float ds = props.get_diffusestrength ();
float ss = props.get_specularstrength ();
float se = props.get_specularexponent ();
- float cb[4] = { 0, 0, 0, 1 };
+ float cb[4] = { 0.0, 0.0, 0.0, 1.0 };
+ double d = 1.0;
opengl_texture tex;
@@ -1800,11 +1801,11 @@
if (fl_mode > 0)
{
for (int i = 0; i < 3; i++)
- cb[i] = (as * fcolor(i));
+ cb[i] = as * fcolor(i);
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int i = 0; i < 3; i++)
- cb[i] *= (ds / as);
+ cb[i] = ds * fcolor(i);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
@@ -1855,12 +1856,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j-1, i-1, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
- if (fl_mode > 0)
- glNormal3d (n(j-1,i-1,0), n(j-1,i-1,1), n(j-1,i-1,2));
+ if (fl_mode > 0)
+ {
+ d = sqrt(n(j-1,i-1,0) * n(j-1,i-1,0)
+ + n(j-1,i-1,1) * n(j-1,i-1,1)
+ + n(j-1,i-1,2) * n(j-1,i-1,2));
+ glNormal3d (n(j-1,i-1,0)/d, n(j-1,i-1,1)/d,
n(j-1,i-1,2)/d);
+ }
glVertex3d (x(j1,i-1), y(j-1,i1), z(j-1,i-1));
// Vertex 2
@@ -1879,12 +1885,19 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j-1, i, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
- if (fl_mode == 2)
- glNormal3d (n(j-1,i,0), n(j-1,i,1), n(j-1,i,2));
+
+ if (fl_mode == 2)
+ {
+ d = sqrt(n(j-1,i,0) * n(j-1,i,0)
+ + n(j-1,i,1) * n(j-1,i,1)
+ + n(j-1,i,2) * n(j-1,i,2));
+ glNormal3d (n(j-1,i,0)/d, n(j-1,i,1)/d, n(j-1,i,2)/d);
+ }
+
glVertex3d (x(j1,i), y(j-1,i2), z(j-1,i));
// Vertex 3
@@ -1903,14 +1916,19 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j, i, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
if (fl_mode == 2)
- glNormal3d (n(j,i,0), n(j,i,1), n(j,i,2));
+ {
+ d = sqrt(n(j,i,0) * n(j,i,0)
+ + n(j,i,1) * n(j,i,1)
+ + n(j,i,2) * n(j,i,2));
+ glNormal3d (n(j,i,0)/d, n(j,i,1)/d, n(j,i,2)/d);
+ }
glVertex3d (x(j2,i), y(j,i2), z(j,i));
-
+
// Vertex 4
if (fc_mode == 3)
tex.tex_coord (double (i-1) / (zc-1), double (j) / (zr-1));
@@ -1927,12 +1945,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j, i-1, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
- if (fl_mode == 2)
- glNormal3d (n(j,i-1,0), n(j,i-1,1), n(j,i-1,2));
+ if (fl_mode == 2)
+ {
+ d = sqrt(n(j,i-1,0) * n(j,i-1,0)
+ + n(j,i-1,1) * n(j,i-1,1)
+ + n(j,i-1,2) * n(j,i-1,2));
+ glNormal3d (n(j,i-1,0)/d, n(j,i-1,1)/d, n(j,i-1,2)/d);
+ }
glVertex3d (x(j2,i-1), y(j,i1), z(j,i-1));
glEnd ();
@@ -1962,11 +1985,11 @@
if (fl_mode > 0)
{
for (int i = 0; i < 3; i++)
- cb[i] = (as * ecolor(i));
+ cb[i] = as * ecolor(i);
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int i = 0; i < 3; i++)
- cb[i] *= (ds / as);
+ cb[i] = ds * ecolor(i);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
@@ -2017,12 +2040,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j-1, i, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
if (el_mode > 0)
- glNormal3d (n(j-1,i,0), n(j-1,i,1), n(j-1,i,2));
+ {
+ d = sqrt(n(j-1,i,0) * n(j-1,i,0)
+ + n(j-1,i,1) * n(j-1,i,1)
+ + n(j-1,i,2) * n(j-1,i,2));
+ glNormal3d (n(j-1,i,0)/d, n(j-1,i,1)/d, n(j-1,i,2)/d);
+ }
glVertex3d (x(j1,i), y(j-1,i2), z(j-1,i));
// Vertex 2
@@ -2039,12 +2067,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j, i, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
if (el_mode == 2)
- glNormal3d (n(j,i,0), n(j,i,1), n(j,i,2));
+ {
+ d = sqrt(n(j,i,0) * n(j,i,0)
+ + n(j,i,1) * n(j,i,1)
+ + n(j,i,2) * n(j,i,2));
+ glNormal3d (n(j,i,0)/d, n(j,i,1)/d, n(j,i,2)/d);
+ }
glVertex3d (x(j2,i), y(j,i2), z(j,i));
glEnd ();
@@ -2091,12 +2124,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j, i-1, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
if (el_mode > 0)
- glNormal3d (n(j,i-1,0), n(j,i-1,1), n(j,i-1,2));
+ {
+ d = sqrt(n(j,i-1,0) * n(j,i-1,0)
+ + n(j,i-1,1) * n(j,i-1,1)
+ + n(j,i-1,2) * n(j,i-1,2));
+ glNormal3d (n(j,i-1,0)/d, n(j,i-1,1)/d, n(j,i-1,2)/d);
+ }
glVertex3d (x(j2,i-1), y(j,i1), z(j,i-1));
// Vertex 2
@@ -2113,12 +2151,17 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int k = 0; k < 3; k++)
- cb[k] *= (ds / as);
+ cb[k] = ds * c(j, i, k);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
if (el_mode == 2)
- glNormal3d (n(j,i,0), n(j,i,1), n(j,i,2));
+ {
+ d = sqrt(n(j,i,0) * n(j,i,0)
+ + n(j,i,1) * n(j,i,1)
+ + n(j,i,2) * n(j,i,2));
+ glNormal3d (n(j,i,0)/d, n(j,i,1)/d, n(j,i,2)/d);
+ }
glVertex3d (x(j2,i), y(j,i2), z(j,i));
glEnd ();
@@ -2364,7 +2407,7 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int i = 0; i < 3; i++)
- cb[i] *= (ds / as);
+ cb[i] = ds * fcolor(i);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}
@@ -2420,7 +2463,7 @@
glMaterialfv (LIGHT_MODE, GL_AMBIENT, cb);
for (int i = 0; i < 3; i++)
- cb[i] *= (ds / as);
+ cb[i] = ds * ecolor(i);
glMaterialfv (LIGHT_MODE, GL_DIFFUSE, cb);
}
}