void Create3DSimplexNoiseVolumeVDB()
{
// Randomize the filename incase the file already exists
System.Random randomIntGenerator = new System.Random();
int randomInt = randomIntGenerator.Next();
string saveLocation = Paths.voxelDatabases + "/3d-simplex-noise-" + randomInt + ".vdb";
// The size of the volume we will generate
int width = 256;
int height = 256;
int depth = 256;
TerrainVolumeData data = VolumeData.CreateEmptyVolumeData <TerrainVolumeData>(new Region(0, 0, 0, width - 1, height - 1, depth - 1), saveLocation);
// This scale factor comtrols the size of the rocks which are generated.
float rockScale = 32.0f;
float invRockScale = 1.0f / rockScale;
// Let's keep the allocation outside of the loop.
MaterialSet materialSet = new MaterialSet();
// Iterate over every voxel of our volume
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
// Make sure we don't have anything left in here from the previous voxel
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
// Simplex noise is quite high frequency. We scale the sample position to reduce this.
float sampleX = (float)x * invRockScale;
float sampleY = (float)y * invRockScale;
float sampleZ = (float)z * invRockScale;
// Get the noise value for the current position.
// Returned value should be in the range -1 to +1.
float simplexNoiseValue = SimplexNoise.Noise.Generate(sampleX, sampleY, sampleZ);
// Cubiquity renders anything below the threshold as empty and anythng above as solid, but
// in general it is easiest if empty space is completly empty and solid space is completly
// solid. The exception to this is the region near our surface, where a gentle transition helps
// obtain smooth shading. By scaling by a large number and then clamping we achieve this effect
// of making most voxels fully solid or fully empty except near the surface..
simplexNoiseValue *= 5.0f;
simplexNoiseValue = Mathf.Clamp(simplexNoiseValue, -0.5f, 0.5f);
// Go back to the range 0.0 to 1.0;
simplexNoiseValue += 0.5f;
// And then to 0 to 255, ready to convert into a byte.
simplexNoiseValue *= 255;
// Write the final value value into the first material channel (the one with the rock texture).
// The value being written is usually 0 (empty) or 255 (solid) except around the transition.
materialSet.weights[0] = (byte)simplexNoiseValue;
// We can now write our computed voxel value into the volume.
data.SetVoxel(x, y, z, materialSet);
}
}
}
// We need to commit this so that the changes made by the previous,line are actually written
// to the voxel database. Otherwise they are just kept in temporary storage and will be lost.
data.CommitChanges();
Debug.Log("Voxel database has been saved to '" + saveLocation + "'");
}
public static void GeneratePlanet(TerrainVolumeData volumeData, float planetRadius, float mat1Radius, float mat2Radius, float mat3Radius)
{
Region volumeBounds = volumeData.enclosingRegion;
MaterialSet materialSet = new MaterialSet();
for(int z = volumeBounds.lowerCorner.z; z <= volumeBounds.upperCorner.z; z++)
{
for(int y = volumeBounds.lowerCorner.y; y <= volumeBounds.upperCorner.y; y++)
{
for(int x = volumeBounds.lowerCorner.x; x <= volumeBounds.upperCorner.x; x++)
{
// We are going to compute our density value based on the distance of a voxel from the center of our planet.
// This is a function which (by definition) is zero at the center of the planet and has a smoothly increasing
// value as we move away from the center.
//
// Note: For efficiency we could probably adapt this to work with squared distances (thereby eliminating
// the square root operation), but we'd like to keep this example as intuitive as possible.
float distFromCenter = Mathf.Sqrt(x * x + y * y + z * z);
// We actually want our volume to have high values in the center and low values as we move out, because our
// eath should be a solid sphere surrounded by empty space. If we invert the distance then this is a step in
// the right direction. We still have zero in the center, but lower (negative) values as we move out.
float density = -distFromCenter;
// By adding the 'planetRadius' we now have a function which starts at 'planetRadius' and still decreases as it
// moves out. The function passes through zero at a distance of 'planetRadius' and then continues do decrease
// as it gets even further out.
density += planetRadius;
// Ideally we would like our final density value to be '255' for voxels inside the planet and '0' for voxels
// outside the planet. At the surface there should be a transition but this should occur not too quickly and
// not too slowly, as both of these will result in a jagged appearance to the mesh.
//
// We probably want the transition to occur over a few voxels, whereas it currently occurs over 255 voxels
// because it was derived from the distance. By scaling the density field we effectivly compress the rate
// at which it changes at the surface. We also make the center much too high and the outside very low, but
// we will clamp these to the corect range later.
//
// Note: You can try commenting out or changing the value on this line to see the effect it has.
density *= 50;
// Until now we've been defining our density field as if the threshold was at zero, with positive densities
// being solid and negative densities being empty. But actually Cubiquity operates on the range 0 to 255, and
// uses a threashold of 127 to decide where to place the generated surface. Therefore we shift and clamp our
// density value and store it in a byte.
density += 127;
byte densityAsByte = (byte)(Mathf.Clamp(density, 0, 255));
if(distFromCenter < mat3Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
materialSet.weights[3] = densityAsByte;
}
else if(distFromCenter < mat2Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = densityAsByte;
materialSet.weights[3] = 0;
}
else if(distFromCenter < mat1Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = densityAsByte;
materialSet.weights[2] = 0;
materialSet.weights[3] = 0;
}
else //Surface material
{
materialSet.weights[0] = densityAsByte;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
materialSet.weights[3] = 0;
}
volumeData.SetVoxel(x, y, z, materialSet);
}
}
}
}
void Create2DSimplexNoiseVolumeVDB()
{
// Randomize the filename incase the file already exists
System.Random randomIntGenerator = new System.Random();
int randomInt = randomIntGenerator.Next();
string saveLocation = Paths.voxelDatabases + "/2d-simplex-noise-" + randomInt + ".vdb";
// The size of the volume we will generate
int width = 256;
int height = 32;
int depth = 256;
TerrainVolumeData data = VolumeData.CreateEmptyVolumeData <TerrainVolumeData>(new Region(0, 0, 0, width - 1, height - 1, depth - 1), saveLocation);
// This scale factor comtrols the size of the rocks which are generated.
float rockScale = 32.0f;
float invRockScale = 1.0f / rockScale;
// Let's keep the allocation outside of the loop.
MaterialSet materialSet = new MaterialSet();
// Iterate over every voxel of our volume
for (int z = 0; z < depth; z++)
{
for (int x = 0; x < width; x++)
{
// Simplex noise is quite high frequency. We scale the sample position to reduce this.
float sampleX = (float)x * invRockScale;
float sampleZ = (float)z * invRockScale;
// Get the noise value for the current position.
// Returned value should be in the range -1 to +1.
float simplexNoiseValue = SimplexNoise.Noise.Generate(sampleX, sampleZ);
simplexNoiseValue += 1.0f;
simplexNoiseValue *= 16.0f;
for (int y = 0; y < height; y++)
{
// Make sure we don't have anything left in here from the previous voxel
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
if (y < simplexNoiseValue)
{
// Write the final value value into the first material channel (the one with the rock texture).
// The value being written is usually 0 (empty) or 255 (solid) except around the transition.
materialSet.weights[0] = (byte)255;
}
// We can now write our computed voxel value into the volume.
data.SetVoxel(x, y, z, materialSet);
}
}
}
// We need to commit this so that the changes made by the previous,line are actually written
// to the voxel database. Otherwise they are just kept in temporary storage and will be lost.
data.CommitChanges();
Debug.Log("Voxel database has been saved to '" + saveLocation + "'");
}
public static void GeneratePlanet(TerrainVolumeData volumeData, float planetRadius, float mat1Radius, float mat2Radius, float mat3Radius)
{
Region volumeBounds = volumeData.enclosingRegion;
MaterialSet materialSet = new MaterialSet();
for (int z = volumeBounds.lowerCorner.z; z <= volumeBounds.upperCorner.z; z++)
{
for (int y = volumeBounds.lowerCorner.y; y <= volumeBounds.upperCorner.y; y++)
{
for (int x = volumeBounds.lowerCorner.x; x <= volumeBounds.upperCorner.x; x++)
{
// We are going to compute our density value based on the distance of a voxel from the center of our planet.
// This is a function which (by definition) is zero at the center of the planet and has a smoothly increasing
// value as we move away from the center.
//
// Note: For efficiency we could probably adapt this to work with squared distances (thereby eliminating
// the square root operation), but we'd like to keep this example as intuitive as possible.
float distFromCenter = Mathf.Sqrt(x * x + y * y + z * z);
// We actually want our volume to have high values in the center and low values as we move out, because our
// eath should be a solid sphere surrounded by empty space. If we invert the distance then this is a step in
// the right direction. We still have zero in the center, but lower (negative) values as we move out.
float density = -distFromCenter;
// By adding the 'planetRadius' we now have a function which starts at 'planetRadius' and still decreases as it
// moves out. The function passes through zero at a distance of 'planetRadius' and then continues do decrease
// as it gets even further out.
density += planetRadius;
// Ideally we would like our final density value to be '255' for voxels inside the planet and '0' for voxels
// outside the planet. At the surface there should be a transition but this should occur not too quickly and
// not too slowly, as both of these will result in a jagged appearance to the mesh.
//
// We probably want the transition to occur over a few voxels, whereas it currently occurs over 255 voxels
// because it was derived from the distance. By scaling the density field we effectivly compress the rate
// at which it changes at the surface. We also make the center much too high and the outside very low, but
// we will clamp these to the corect range later.
//
// Note: You can try commenting out or changing the value on this line to see the effect it has.
density *= 50;
// Until now we've been defining our density field as if the threshold was at zero, with positive densities
// being solid and negative densities being empty. But actually Cubiquity operates on the range 0 to 255, and
// uses a threashold of 127 to decide where to place the generated surface. Therefore we shift and clamp our
// density value and store it in a byte.
density += 127;
byte densityAsByte = (byte)(Mathf.Clamp(density, 0, 255));
if (distFromCenter < mat3Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
materialSet.weights[3] = densityAsByte;
}
else if (distFromCenter < mat2Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = 0;
materialSet.weights[2] = densityAsByte;
materialSet.weights[3] = 0;
}
else if (distFromCenter < mat1Radius)
{
materialSet.weights[0] = 0;
materialSet.weights[1] = densityAsByte;
materialSet.weights[2] = 0;
materialSet.weights[3] = 0;
}
else //Surface material
{
materialSet.weights[0] = densityAsByte;
materialSet.weights[1] = 0;
materialSet.weights[2] = 0;
materialSet.weights[3] = 0;
}
volumeData.SetVoxel(x, y, z, materialSet);
}
}
}
}
