Cycles: remove support for rendering hair as triangle and lines

Triangles were very memory intensive. The only reason they were not removed yet
is that they gave more accurate results, but there will be an accurate 3D curve
primitive added for this.

Line rendering was always poor quality since the ends do not match up. To keep CPU
and GPU compatibility we just remove them entirely. They could be brought back if
an Embree compatible implementation is added, but it's not clear to me that there
is a use case for these that we'd consider important.

Ref T73778

Reviewers: #cycles

Subscribers:

1 files changed, 8 insertions, 33 deletions

diff --git a/intern/cycles/render/curves.cpp b/intern/cycles/render/curves.cpp
index 1907bb33d06..a223702cfab 100644
--- a/intern/cycles/render/curves.cpp
+++ b/intern/cycles/render/curves.cpp
@@ -81,17 +81,11 @@ void curvebounds(float *lower, float *upper, float3 *p, int dim)
 
 CurveSystemManager::CurveSystemManager()
 {
-  primitive = CURVE_LINE_SEGMENTS;
   curve_shape = CURVE_THICK;
-  line_method = CURVE_CORRECTED;
-  triangle_method = CURVE_CAMERA_TRIANGLES;
-  resolution = 3;
   subdivisions = 3;
 
   use_curves = true;
-  use_encasing = true;
   use_backfacing = false;
-  use_tangent_normal_geometry = false;
 
   need_update = true;
   need_mesh_update = false;
@@ -118,22 +112,12 @@ void CurveSystemManager::device_update(Device *device,
   kcurve->curveflags = 0;
 
   if (use_curves) {
-    if (primitive == CURVE_SEGMENTS || primitive == CURVE_RIBBONS)
-      kcurve->curveflags |= CURVE_KN_INTERPOLATE;
-    if (primitive == CURVE_RIBBONS)
+    if (curve_shape == CURVE_RIBBON) {
       kcurve->curveflags |= CURVE_KN_RIBBONS;
-
-    if (line_method == CURVE_ACCURATE)
-      kcurve->curveflags |= CURVE_KN_ACCURATE;
-    else if (line_method == CURVE_CORRECTED)
-      kcurve->curveflags |= CURVE_KN_INTERSECTCORRECTION;
-
-    if (use_tangent_normal_geometry)
-      kcurve->curveflags |= CURVE_KN_TRUETANGENTGNORMAL;
-    if (use_backfacing)
+    }
+    else if (use_backfacing) {
       kcurve->curveflags |= CURVE_KN_BACKFACING;
-    if (use_encasing)
-      kcurve->curveflags |= CURVE_KN_ENCLOSEFILTER;
+    }
 
     kcurve->subdivisions = subdivisions;
   }
@@ -150,23 +134,14 @@ void CurveSystemManager::device_free(Device * /*device*/, DeviceScene * /*dscene
 
 bool CurveSystemManager::modified(const CurveSystemManager &CurveSystemManager)
 {
-  return !(
-      curve_shape == CurveSystemManager.curve_shape &&
-      line_method == CurveSystemManager.line_method && primitive == CurveSystemManager.primitive &&
-      use_encasing == CurveSystemManager.use_encasing &&
-      use_tangent_normal_geometry == CurveSystemManager.use_tangent_normal_geometry &&
-      use_backfacing == CurveSystemManager.use_backfacing &&
-      triangle_method == CurveSystemManager.triangle_method &&
-      resolution == CurveSystemManager.resolution && use_curves == CurveSystemManager.use_curves &&
-      subdivisions == CurveSystemManager.subdivisions);
+  return !(use_backfacing == CurveSystemManager.use_backfacing &&
+           use_curves == CurveSystemManager.use_curves &&
+           subdivisions == CurveSystemManager.subdivisions);
 }
 
 bool CurveSystemManager::modified_mesh(const CurveSystemManager &CurveSystemManager)
 {
-  return !(
-      primitive == CurveSystemManager.primitive && curve_shape == CurveSystemManager.curve_shape &&
-      triangle_method == CurveSystemManager.triangle_method &&
-      resolution == CurveSystemManager.resolution && use_curves == CurveSystemManager.use_curves);
+  return !(use_curves == CurveSystemManager.use_curves);
 }
 
 void CurveSystemManager::tag_update(Scene * /*scene*/)