Alembic Procedural: basic cache control settings

This adds a setting to enable data caching, and another one to set the
maximum cache size in megabytes.

When caching is enabled we load the data for the entire animation in
memory, as we already do, however, if the data exceeds the memory limit,
render is aborted.

When caching is disabled, we simply load the data for the current frame
in memory.

Ref D10197

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D11163

1 files changed, 13 insertions, 3 deletions

diff --git a/intern/cycles/render/alembic_read.cpp b/intern/cycles/render/alembic_read.cpp
index c53ec668938..b105af63b44 100644
--- a/intern/cycles/render/alembic_read.cpp
+++ b/intern/cycles/render/alembic_read.cpp
@@ -44,9 +44,19 @@ static set<chrono_t> get_relevant_sample_times(AlembicProcedural *proc,
     return result;
   }
 
-  // load the data for the entire animation
-  const double start_frame = static_cast<double>(proc->get_start_frame());
-  const double end_frame = static_cast<double>(proc->get_end_frame());
+  double start_frame;
+  double end_frame;
+
+  if (proc->get_use_prefetch()) {
+    // load the data for the entire animation
+    start_frame = static_cast<double>(proc->get_start_frame());
+    end_frame = static_cast<double>(proc->get_end_frame());
+  }
+  else {
+    // load the data for the current frame
+    start_frame = static_cast<double>(proc->get_frame());
+    end_frame = start_frame;
+  }
 
   const double frame_rate = static_cast<double>(proc->get_frame_rate());
   const double start_time = start_frame / frame_rate;