Add instancing distance culling, scale deformation

* GPU instance distance culling now takes a min/max range
* Fold recovers ops from material, allowing state to persist across
  editor restarts
* Add scale node to vertex deformation framework
* Remove fold presets - dumb LLM idea, unused
* Drop more "undeform" code; unused, was for ray marching, which does
  not work well
* Fix reflection energy compensation; was using cloth math, which makes
  things too bright

1 files changed, 11 insertions, 92 deletions

diff --git a/vertex_deformation.slang b/vertex_deformation.slang
index 1cb002f..0c25d76 100755
--- a/vertex_deformation.slang
+++ b/vertex_deformation.slang
@@ -53,18 +53,6 @@
   normal = mul(itjac, normal) * jac_det;            \
   tangent = mul(jacobian, tangent) * jac_det
 
-#define R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent) \
-  float3x3 jacobian = float3x3(                           \
-    float3(dp_x_out.d.x, dp_y_out.d.x, dp_z_out.d.x),     \
-    float3(dp_x_out.d.y, dp_y_out.d.y, dp_z_out.d.y),     \
-    float3(dp_x_out.d.z, dp_y_out.d.z, dp_z_out.d.z)      \
-  );                                                      \
-  float jac_det = determinant(jacobian);                  \
-  float3x3 inv_jac = inverse(jacobian, jac_det);          \
-  float3x3 trans_jac = transpose(jacobian);               \
-  normal = mul(trans_jac, normal) * jac_det; \
-  tangent = mul(inv_jac, tangent) * jac_det
-
 // Syntactic sugar - wraps the previous three macros.
 #define R3R3_NORMALS(xyz, normal, tangent, fun, ...)  \
   R3R3_DECLARE_BASIS_VECTORS(xyz);                    \
@@ -111,7 +99,7 @@ public float3 plane_to_tube(float3 xyz,
   s_cart = normalize(s_cart);
   float3 rxs_cart = cross(s_cart, r_cart);
   float3x3 to_rsrxs = float3x3(r_cart, s_cart, rxs_cart);
-  // Ivnerse of orthonormal matrix is just the transpose.
+  // Inverse of orthonormal matrix is just the transpose.
   float3x3 to_cart  = transpose(to_rsrxs);
 
   // Translate origin to `p` then change into (r, s, r x s) basis.
@@ -154,13 +142,6 @@ public void plane_to_tube_normal(inout float3 xyz, inout float3 normal,
   R3R3_NORMALS(xyz, normal, tangent, plane_to_tube, p, r, s, t);
 }
 
-public void plane_to_tube_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float3 p, float3 r, float3 s, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(plane_to_tube, p, r, s, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 public float3 axis_align(float3 xyz, no_diff float3 po, no_diff float3 pp, no_diff float3 r, no_diff float t) {
   const float3 xyz0 = xyz;
@@ -206,13 +187,6 @@ public void axis_align_normal(inout float3 xyz, inout float3 normal,
   R3R3_NORMALS(xyz, normal, tangent, axis_align, po, pp, r, t);
 }
 
-public void axis_align_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float3 po, float3 pp, float3 r, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(axis_align, po, pp, r, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 // Maps a tube with circular cross section on the xz plane to a quad on the xy
 // plane.
 [Differentiable]
@@ -274,14 +248,6 @@ public void tube_to_plane_normal(inout float3 xyz, inout float3 normal,
   R3R3_NORMALS(xyz, normal, tangent, tube_to_plane, p, r, s, t);
 }
 
-public void tube_to_plane_undeform_normal(
-    float3 xyz, inout float3 normal, inout float3 tangent,
-    float3 p, float3 r, float3 s, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(tube_to_plane, p, r, s, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 public float3 point_align(float3 xyz, no_diff float3 po, no_diff float3 pp, no_diff float3 r, no_diff float t) {
   const float3 xyz0 = xyz;
@@ -320,12 +286,6 @@ public void point_align_normal(inout float3 xyz, inout float3 normal, inout floa
   R3R3_NORMALS(xyz, normal, tangent, point_align, po, pp, r, t);
 }
 
-public void point_align_undeform_normal(float3 xyz, inout float3 normal, inout float3 tangent, float3 po, float3 pp, float3 r, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(point_align, po, pp, r, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 public float3 seal(float3 xyz, no_diff float A, no_diff float k, no_diff float t) {
   float x = xyz.x;
@@ -352,13 +312,6 @@ public void seal_normal(inout float3 xyz, inout float3 normal,
   R3R3_NORMALS(xyz, normal, tangent, seal, A, k, t);
 }
 
-public void seal_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float A, float k, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(seal, A, k, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 public float3 sine_wave(float3 xyz,
     no_diff float3 amplitude,
@@ -375,14 +328,6 @@ public void sine_wave_normal(inout float3 xyz, inout float3 normal, inout float3
   R3R3_NORMALS(xyz, normal, tangent, sine_wave, amplitude, direction, k, omega, t);
 }
 
-public void sine_wave_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float3 amplitude, float3 direction, float3 k,
-    float3 omega, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(sine_wave, amplitude, direction, k, omega, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 public float3 norm_conversion(float3 xyz, no_diff float input_k, no_diff float output_k, no_diff float t) {
   float3 xyz_abs = abs(xyz)+1e-4f;
@@ -396,12 +341,6 @@ public void norm_conversion_normal(inout float3 xyz, inout float3 normal, inout
   R3R3_NORMALS(xyz, normal, tangent, norm_conversion, input_k, output_k, t);
 }
 
-public void norm_conversion_undeform_normal(float3 xyz, inout float3 normal, inout float3 tangent, float input_k, float output_k, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(norm_conversion, input_k, output_k, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 [Differentiable]
 float3 rand3_hash3(float3 p)
 {
@@ -544,24 +483,6 @@ public void fbm_normal(inout float3 xyz, inout float3 normal, inout float3 tange
   tangent = mul(jac, tangent);
 }
 
-public void fbm_undeform_normal(float3 xyz, float t,
-    float3 amplitude, float gain, float lacunarity,
-    float3 period, float octaves, float3 velocity,
-    inout float3 normal, inout float3 tangent) {
-  float3 dx, dy, dz;
-  fbm_with_derivatives(xyz, t, amplitude, gain, lacunarity, period, octaves,
-      velocity, dx, dy, dz);
-  float3x3 jac = float3x3(
-      dx.x, dy.x, dz.x,
-      dx.y, dy.y, dz.y,
-      dx.z, dy.z, dz.z);
-  float jac_det = determinant(jac);
-  float3x3 inv_jac = inverse(jac, jac_det);
-  float3x3 trans_jac = transpose(jac);
-  normal = mul(trans_jac, normal) * jac_det;
-  tangent = mul(inv_jac, tangent);
-}
-
 // Maps a plane to a hemi-octahedron (half octahedron).
 // Uses octahedral parameterization consistent with pbrt's OctahedralVector.
 // Input: plane on [-1,1]² in the (r, rxs) plane
@@ -618,13 +539,6 @@ public void plane_to_hemi_octahedron_normal(inout float3 xyz, inout float3 norma
   R3R3_NORMALS(xyz, normal, tangent, plane_to_hemi_octahedron, p, r, s, t);
 }
 
-public void plane_to_hemi_octahedron_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float3 p, float3 r, float3 s, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(plane_to_hemi_octahedron, p, r, s, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
-}
-
 // Maps a hemi-octahedron to a plane (inverse of plane_to_hemi_octahedron).
 // Input: unit hemisphere with pole at +s direction
 // Output: plane on [-1,1]² in the (r, rxs) plane
@@ -676,11 +590,16 @@ public void hemi_octahedron_to_plane_normal(inout float3 xyz, inout float3 norma
   R3R3_NORMALS(xyz, normal, tangent, hemi_octahedron_to_plane, p, r, s, t);
 }
 
-public void hemi_octahedron_to_plane_undeform_normal(float3 xyz, inout float3 normal,
-    inout float3 tangent, float3 p, float3 r, float3 s, float t) {
-  R3R3_DECLARE_BASIS_VECTORS(xyz);
-  R3R3_AUTODIFF_BASIS_VECTORS(hemi_octahedron_to_plane, p, r, s, t);
-  R3R3_UNDEFORM_NORMAL_AND_TANGENT(normal, tangent);
+[Differentiable]
+public float3 scale(float3 xyz,
+    no_diff float3 k, no_diff float t) {
+  return dlerp(xyz, xyz * k, t);
+}
+
+public void scale_normal(inout float3 xyz, inout float3 normal,
+    inout float3 tangent, float3 k, float t) {
+  R3R3_NORMALS(xyz, normal, tangent, scale, k, t);
 }
 
 #endif  // __CUSTOM31_INC
+