An image laid onto a model came out upside down under the ordinary box
(tri-planar) projection, and on three of a cube's six faces it was also
mirrored left to right, which reads as a 180 degree rotation.
DecodedHeightTexture::sample() defines v = 0 as the height map's first
pixel row, i.e. its top. Every projection built v from world +Z, so v
grew upward and the image landed bottom row up. The one path that was
already right is the projective "project from view" matrix, which
measures window y downward.
Both halves of the box basis were wrong:
- v is now negated on all three world planes, so the top of an image
sits at the top of the model.
- u now carries a sign for the side of the plane the face is on, chosen
so that u x v == -normal. Without it the two faces sharing a plane get
one u and one of them is mirrored. The sign flips exactly where that
plane's blend weight (the fourth power of a normal component) reaches
zero, so the blended tri-planar sum stays continuous and the hard axis
switch the old code removed does not come back.
The same v convention was missing from the other mapping modes:
cylindrical (which also had a left handed frame, right x up rather than
up x right, so its wrap ran mirrored), spherical, the affine branch of
view projection, and the flat chart fallback of the LSCM unwrap, which
now reuses the box basis so a cube face unwraps to the orientation
tri-planar would have given it.
The basis table is exported as box_projection_axes() and the gizmo's
adjust_tangent_basis() calls it instead of restating it, so the
placement ring and offset handle cannot drift from the bake. All four
preview shaders get the matching change, including projection_axes(),
whose tangent and bitangent have to flip with the coordinate or the
relief shading inverts.
Re-baking an existing project now places its texture upright, so it will
differ from how it looked before. Geometry already baked into a 3mf is
untouched, so nothing changes until the user re-bakes.
Verified by measuring the sampled texture row and column against world
position for every mapping mode on all six faces of a cube, and by a
full bake of a quadrant coded image, which lands each quadrant within
1e-3 mm of its expected depth.
- Bake: each layer is sampled only on its own painted area; analytic
projections used to stack every layer over every painted region, so the
top layer's texture showed on all of them (colour sampler too)
- Auto resolution follows the texture's texel size and sharpness again
- Unwrap: charts cut by each face's own normal (a cube gives 6 islands, not
12 triangles); non-disk charts (tubes, closed shells) are split until they
flatten; connected nets test real triangle overlap, grow from the largest
chart and are packed side by side
- UV edits are stored per unwrapped copy, so dragging a seam vertex no
longer moves its copies in neighbouring islands
- UV pane: tool strip with unwrap settings moved in from the panel, sharp
HiDPI icons, clearer island/edge/selection drawing with hover, texture
picker from the thumbnail, texture no longer lost on reopen (GL state
from the 3D view, background upload retries)
- Panel: whole-model select/erase as icons in the tools row; inactive
layers' paint shown muted; colour textures shown in colour in the picker
- Built-in displacement texture library
- Tests for unwrap segmentation, connected nets, UV edits and per-layer
sampling
ExPikaPaka