Cycles: change volume step size controls, auto adjust based on voxel size

By default it will now set the step size to the voxel size for smoke and
volume objects, and 1/10th the bounding box for procedural volume shaders.

New settings are:
* Scene render/preview step rate: to globally adjust detail and performance
* Material step rate: multiplied with auto detected per-object step size
* World step size: distance to steo for world shader

Differential Revision: https://developer.blender.org/D1777

1 files changed, 2 insertions, 0 deletions

diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index dc226805664..59c1539d207 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -1260,6 +1260,7 @@ void BlenderSync::sync_materials(BL::Depsgraph &b_depsgraph, bool update_all)
       shader->heterogeneous_volume = !get_boolean(cmat, "homogeneous_volume");
       shader->volume_sampling_method = get_volume_sampling(cmat);
       shader->volume_interpolation_method = get_volume_interpolation(cmat);
+      shader->volume_step_rate = get_float(cmat, "volume_step_rate");
       shader->displacement_method = get_displacement_method(cmat);
 
       shader->set_graph(graph);
@@ -1324,6 +1325,7 @@ void BlenderSync::sync_world(BL::Depsgraph &b_depsgraph, BL::SpaceView3D &b_v3d,
       shader->heterogeneous_volume = !get_boolean(cworld, "homogeneous_volume");
       shader->volume_sampling_method = get_volume_sampling(cworld);
       shader->volume_interpolation_method = get_volume_interpolation(cworld);
+      shader->volume_step_rate = get_float(cworld, "volume_step_size");
     }
     else if (new_viewport_parameters.use_scene_world && b_world) {
       BackgroundNode *background = new BackgroundNode();