Tweak the pressure/size dynamic range of Clay Strips

The current clay strips brush has a huge dynamic range which is nice for
certain effects, but in some pen tablets it is quite hard to control on
the higher values and it ends up producing unwanted artifacts. This
changes the input curves a bit in an attempt to make it more
controllable.

After adding a brush management system I will expose all these values to
be configurable per brush (the round version of clay strips is a little
bit better with different curves, but that is something that we can't
support now), but for now this default are probably safer.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D7524

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 7bd7714b725..ce5433f680e 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -2100,7 +2100,7 @@ static float brush_strength(const Sculpt *sd,
       return alpha * pressure * overlap * feather * 2.0f;
     case SCULPT_TOOL_CLAY_STRIPS:
       /* Clay Strips needs less strength to compensate the curve. */
-      final_pressure = pressure * pressure * pressure;
+      final_pressure = powf(pressure, 1.5f);
       return alpha * flip * final_pressure * overlap * feather * 0.3f;
     case SCULPT_TOOL_CLAY_THUMB:
       final_pressure = pressure * pressure;
@@ -4624,7 +4624,7 @@ static void do_clay_strips_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int t
   const bool flip = (ss->cache->bstrength < 0.0f);
   const float radius = flip ? -ss->cache->radius : ss->cache->radius;
   const float offset = SCULPT_brush_plane_offset_get(sd, ss);
-  const float displace = radius * (0.25f + offset);
+  const float displace = radius * (0.18f + offset);
 
   /* The sculpt-plane normal (whatever its set to). */
   float area_no_sp[3];
@@ -6189,7 +6189,7 @@ static float sculpt_brush_dynamic_size_get(Brush *brush, StrokeCache *cache, flo
     case SCULPT_TOOL_CLAY:
       return max_ff(initial_size * 0.20f, initial_size * pow3f(cache->pressure));
     case SCULPT_TOOL_CLAY_STRIPS:
-      return max_ff(initial_size * 0.30f, initial_size * pow2f(cache->pressure));
+      return max_ff(initial_size * 0.30f, initial_size * powf(cache->pressure, 1.5f));
     case SCULPT_TOOL_CLAY_THUMB: {
       float clay_stabilized_pressure = sculpt_clay_thumb_get_stabilized_pressure(cache);
       return initial_size * clay_stabilized_pressure;