Original Post
I am working on terrain transitioning for heightmaps but I am having problems with the blending. What is happening I think is terrain behind bumps get rendered even though they are behind others. But I do not know how to get it to not render stuff that shouldn't be or not get rid of the little yellow spots. I have tried rending closest to farthest and farthest to closest but I can't get ride of the spots. I have also tried changing the perspective and it does not help either. Here is a screen shot of what is happening. HeightMap. I don't know how to fix this so can someone please help. I will post a little code If anyone can help I would appreciate it. Thanks vbuser
void HeightMap::BuildMap() {
buildList = glGenLists(1);
glNewList(buildList,GL_COMPILE);
glBindTexture(GL_TEXTURE_2D,grass); // Bind grass texture
glBegin(GL_QUADS);
for(int z = 0;z < Map_Size - 1;z++) {
for(int x = 0;x < Map_Size - 1;x++) {
float alpha1,alpha2,alpha3,alpha4;
alpha1 = 1.0f - (Alpha(x,z + 1) / 255.0f);
alpha2 = 1.0f - (Alpha(x,z) / 255.0f);
alpha3 = 1.0f - (Alpha(x + 1,z) / 255.0f);
alpha4 = 1.0f - (Alpha(x + 1,z + 1) / 255.0f);
if(alpha1 == 0.0f && alpha2 == 0.0f && alpha3 == 0.0f && alpha4 == 0.0f) {
}
else {
glTexCoord2f(x / 10.0f,(z + 1) / 10.0f);
glColor4f(1.0f,1.0f,1.0f,alpha1);
glVertex3f(x * STEP_SIZE,Height(x,z + 1),-((z + 1)* STEP_SIZE));
glTexCoord2f(x / 10.0f,z / 10.0f);
glColor4f(1.0f,1.0f,1.0f,alpha2);
glVertex3f(x * STEP_SIZE,Height(x,z),-(z * STEP_SIZE));
glTexCoord2f((x + 1) / 10.0f,z / 10.0f);
glColor4f(1.0f,1.0f,1.0f,alpha3);
glVertex3f((x + 1) * STEP_SIZE,Height(x + 1,z),-(z * STEP_SIZE));
glTexCoord2f((x + 1) / 10.0f,(z + 1) / 10.0f);
glColor4f(1.0f,1.0f,1.0f,alpha4);
glVertex3f((x + 1) * STEP_SIZE,Height(x + 1,z + 1),-((z + 1) * STEP_SIZE));
}
}
}
glEnd();
glBindTexture(GL_TEXTURE_2D,sand); // Bind sand texture
glBegin(GL_QUADS);
// Draw sand
for(int z = 0;z < Map_Size - 1;z++) {
for(int x = 0;x < Map_Size - 1;x++) {
float alpha1,alpha2,alpha3,alpha4;
alpha1 = Alpha(x,z + 1) / 255.0f;
alpha2 = Alpha(x,z) / 255.0f;
alpha3 = Alpha(x + 1,z) / 255.0f;
alpha4 = Alpha(x + 1,z + 1) / 255.0f;
if(alpha1 == 0.0f && alpha2 == 0.0f && alpha3 == 0.0f && alpha4 == 0.0f) {
}
else {
glTexCoord2f(x / 2.0f,(z + 1) / 2.0f);
glColor4f(1.0f,1.0f,1.0f,alpha1);
glVertex3f(x * STEP_SIZE,Height(x,z + 1),-((z + 1)* STEP_SIZE));
glTexCoord2f(x / 2.0f,z / 2.0f);
glColor4f(1.0f,1.0f,1.0f,alpha2);
glVertex3f(x * STEP_SIZE,Height(x,z),-(z * STEP_SIZE));
glTexCoord2f((x + 1) / 2.0f,z / 2.0f);
glColor4f(1.0f,1.0f,1.0f,alpha3);
glVertex3f((x + 1) * STEP_SIZE,Height(x + 1,z),-(z * STEP_SIZE));
glTexCoord2f((x + 1) / 2.0f,(z + 1) / 2.0f);
glColor4f(1.0f,1.0f,1.0f,alpha4);
glVertex3f((x + 1) * STEP_SIZE,Height(x + 1,z + 1),-((z + 1) * STEP_SIZE));
}
}
}
glEnd();
glEndList();
}
void HeightMap::Render() {
glColor4f(1.0f,1.0f,1.0l,1.0f); // Reset color
glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glPushMatrix();
glCallList(buildList); // Draw the map
glDisable(GL_BLEND);
glPopMatrix(); // Restore the matrix
glColor4f(1.0f,1.0f,1.0f,1.0f);
}