Seamlessly stitch two HeightFields

[Neikke]

Hey magicians, how would you seamlessly stitch two different heightfields using Vex (or VOPs)? Any ideas would be hugely welcomed!

Edited March 3, 2023 by Neikke

[konstantin magnus]

Hi Natiq,

maybe there is a node for this, but you could overlap both height fields and sample them into a new one:

float band = chf('band');

float h_0 = volumesample(1, 'height', v@P);
float h_1 = volumesample(2, 'height', v@P);

float mask = smooth(-band, band, v@P.x);
f@height = lerp(h_0, h_1, mask);

 

hf_blend.hip

[Neikke]

2 hours ago, konstantin magnus said:

Hi Natiq,

maybe there is a node for this, but you could overlap both height fields and sample them into a new one:

float band = chf('band');

float h_0 = volumesample(1, 'height', v@P);
float h_1 = volumesample(2, 'height', v@P);

float mask = smooth(-band, band, v@P.x);
f@height = lerp(h_0, h_1, mask);

 

hf_blend.hip 171.73 kB · 3 downloads

Hey thanks a lot Konstantin! But will this method work if I need to stitch 6 height maps in this way? I marked areas that need to have perfectly matching relief accordigly:

 

Do you have an idea how to approach this? 

 

[konstantin magnus]

Copy the height fields to the points of an octahedron to shape a cube, apply noise there and assign them to a cross.

 

Alternatively try sampling the world position noise from a cube mesh right away:

int index[] = array(0,2,1,3,5,4);

vector bb = relbbox(0, v@P);
vector uvw = set(bb.x, bb.z, 0.0);
vector pos = primuv(1, 'P', index[i@primnum], uvw);
float height = noise(pos * 50.0) * 200.0;

f@density = height;

 

heightfield_cube.hipnc

[Neikke]

Great thanks I will check that! Thanks a lot!

[konstantin magnus]

1 hour ago, Neikke said:

Great thanks I will check that! Thanks a lot!

I think you would still need to correct the point numbers to really make all the tiles match, but yeah, I'm glad it's useful.

[Richard]

You could us the heightfield layer node to blend them together, overlap them a bit and then just paint a mask to control where the blend happens. 

However, you might be better off just making one big terrain and then making a cross shape extrude it up and use a hf cutout by object.  If that works (I havent tried it) you would no longer have seams on any of the inner edges.

For the outter edges maybe this is easier to solve as a texturing problem?

Write out the Heightfield to disk and then in PS or in COPs, basically clone stamp the edges to get rid of any seams.  Then bring the new seamless texture back in through a heightfield file node. 

[Neikke]

On 3/8/2023 at 2:49 PM, Richard said:

You could us the heightfield layer node to blend them together, overlap them a bit and then just paint a mask to control where the blend happens. 

However, you might be better off just making one big terrain and then making a cross shape extrude it up and use a hf cutout by object.  If that works (I havent tried it) you would no longer have seams on any of the inner edges.

For the outter edges maybe this is easier to solve as a texturing problem?

Write out the Heightfield to disk and then in PS or in COPs, basically clone stamp the edges to get rid of any seams.  Then bring the new seamless texture back in through a heightfield file node. 

Thanks that totally makes sense. I'm not too familiar with COPs but it's definitely possible in PS or in Substance Designer. Thanks a lot for your help!