Morph fields
A field that is a continuous blend between two different things, so the in-between states are real shapes rather than a cross-fade.
What it is
A morph field is a formula that blends one thing into another: a curve melting into a volume, a mesh softening into a blob, one shape becoming a completely different shape.
A dissolve or opacity cross-fade shows two pictures overlapping. A morph field computes a genuine in-between surface at every blend amount. At the halfway point the result is a real, solid shape that is half curve and half volume. Light it, render it, and keep working with it like any other shape.
A morph field is what you get when the two sources cannot be matched up point for point, and that is worth knowing because the like-for-like pairs take shorter routes. Two vector shape collections interpolate their own outlines and stay resolution-free vector shapes, with no distance field anywhere in it. Two meshes blend as meshes: matching vertex counts move vertex for vertex, and mismatched ones blend through a surface distance field and are re-triangulated, but either way a mesh comes out. It is the mixed pairs, a shape against an image, an image against a volume, that produce a real morph field.
There, both sources are read as a Distance Field, those two formulas are blended, and the new surface is read off. Surface colour is sampled from both sources and blended by the same amount, so the tint travels across too. Nothing else about the material does: roughness, metallic and the rest come from whatever material the result is rendered with.
Like every field, a morph is evaluated at every point rather than stored. It has no vertices and no voxels until something downstream asks for them.
When to use one
Shape transitions, one object becoming another over time.
Organic transformation: growing, melting, fusing, the blobby in-between forms a straight mesh blend cannot produce.
Blending across kinds, joining things that are not the same type, such as an Analytic curve and a Volume, with no manual conversion first.
How to use it
Morphing is Mix with Blend turned on. Without it the node is a discrete switch and picks one option outright.
Wire your sources into the option inputs and drive Index. It is not limited to two: the whole number part of Index picks which adjacent pair you are between, and the fraction is the blend across that pair, so a chain of five shapes morphs through all of them as Index runs 0 to 4.
0is fully the first option1is fully the secondanything between is a real blended shape
Drive Index over time to animate the transformation: keyframe it, wire it to a signal, or feed it from any value that travels. The morph re-evaluates continuously, so the motion is smooth at every frame.
Blend Placement is on by default and matters for shapes. It interpolates each shape's position, rotation and scale as well as its outline, so the form travels between the two as it changes. Turn it off to morph in place.
Wire a Curve into Factor, the blend's easing input. An eased blend reads more naturally than a straight linear ramp, and the same curve shapes a shape key, a mesh morph and a morph field alike.
Gotcha
A morph blends across two different kinds of thing, which costs more than a plain Mix between two like values. Each source is turned into a distance field first, and the result has no immediate GPU form, so rendering it converts it into a Volume, or into a mesh where a downstream node needs solid geometry.
Volume and mesh sources are prepared on the CPU for morphing. High-resolution sources make the morph slower to cook, so keep source detail down and bake the result once the transition is right.