added 73 characters in body

Source Link

edited Aug 14, 2014 at 15:09

3
4

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);
ofVec3f v2(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);
         
    
    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
//  v0 - v1
//  | \  |
//  v2 - v3 

// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            
 
    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);
ofVec3f v2(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);
            
    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
//  v0 - v1
//  | \  |
//  v2 - v3 

// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

added 82 characters in body

Source Link

edited Aug 14, 2014 at 15:03

user46759

3
4

How many normals isare needed to have a smooth surface?

I tryI'm trying to draw a a smooth cloth surface. and I have a per pixel-pixel shader. I expect to have a smooth surface but it's not the case. MaybeI think the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ? I still have a flat triangulated surface although I have a per pixel glsl shader

Thanks for help.

How many normals is needed to have a smooth surface?

I try to draw a a smooth cloth surface. I have a per pixel shader. I expect to have a smooth surface but it's not the case. Maybe the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ? I still have a flat triangulated surface although I have a per pixel glsl shader

Thanks for help

How many normals are needed to have a smooth surface?

I'm trying to draw a smooth cloth surface and I have a per-pixel shader. I expect to have a smooth surface but it's not the case. I think the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ? I still have a flat triangulated surface although I have a per pixel glsl shader

Thanks for help.

added 82 characters in body

Source Link

edited Aug 14, 2014 at 14:58

user46759

3
4

I try to draw a a smooth cloth surface. I have a per pixel shader. I expect to have a smooth surface but it's not the case. Maybe the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ? I still have a flat triangulated surface although I have a per pixel glsl shader

Thanks for help

I try to draw a a smooth cloth surface. I have a per pixel shader. I expect to have a smooth surface but it's not the case. Maybe the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ?

Thanks for help

I try to draw a a smooth cloth surface. I have a per pixel shader. I expect to have a smooth surface but it's not the case. Maybe the problem comes from my normals.

The image show the surface drawn with multiple triangles. The surface is lit; the white zone are specular reflection.

enter image description here

Here is the way I calculate normals

ofVec3f v0(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);          
ofVec3f v3(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);         
ofVec3f v1(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);            

    ofVec3f n0 = (v1-v0).cross(v3-v0);
    n0.normalize();
    ofVec3f n2 = (v0-v2).cross(v3-v2);      
    n2.normalize();
    ofVec3f n3 = (v0-v3).cross(v1-v3);      
    n3.normalize();
    ofVec3f n1 = -(v0-v1).cross(v3-v1);     
    n1.normalize();

Here is the code to draw my surface. It's a 64x64 array of double triangles

glBegin(GL_TRIANGLES);

for (int i=0; i<ps.size()-(cols+1); i++) { 
v0 - v1
| \  |
v2 - v3
// v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);


//v1
glNormal3f(n1.x, n1.y, n1.z);
glVertex3f(ps[i+1].pos.x, ps[i+1].pos.y, ps[i+1].pos.z);


//v0
glNormal3f(n0.x, n0.y, n0.z);
glVertex3f(ps[i].pos.x, ps[i].pos.y, ps[i].pos.z);

//v2
glNormal3f(n2.x, n2.y, n2.z);
glVertex3f(ps[i+cols].pos.x, ps[i+cols].pos.y, ps[i+cols].pos.z);

//v3
glNormal3f(n3.x, n3.y, n3.z);
glVertex3f(ps[i+cols+1].pos.x, ps[i+cols+1].pos.y, ps[i+cols+1].pos.z);

I don't know how many normals I need and where to put them: at each vertex, one by face ? four by vertex ? I still have a flat triangulated surface although I have a per pixel glsl shader

Thanks for help

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edited Aug 14, 2014 at 14:28

user46759

3
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edited Aug 14, 2014 at 14:20

user46759

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edited Aug 14, 2014 at 14:14

user46759

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edited Aug 14, 2014 at 14:07

user46759

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edited Aug 14, 2014 at 10:14

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How many normals isare needed to have a smooth surface?

How many normals is needed to have a smooth surface?

How many normals are needed to have a smooth surface?