5 files changed, 53 insertions, 28 deletions

diff --git a/source/blender/render/RE_pipeline.h b/source/blender/render/RE_pipeline.h
index 4534c86f7f7..cd839385bfb 100644
--- a/source/blender/render/RE_pipeline.h
+++ b/source/blender/render/RE_pipeline.h
@@ -155,6 +155,8 @@ typedef struct RenderResult {
   char *error;
 
   struct StampData *stamp_data;
+
+  bool passes_allocated;
 } RenderResult;
 
 typedef struct RenderStats {
diff --git a/source/blender/render/intern/engine.c b/source/blender/render/intern/engine.c
index 75b3f2db249..1510587502b 100644
--- a/source/blender/render/intern/engine.c
+++ b/source/blender/render/intern/engine.c
@@ -212,6 +212,8 @@ static RenderResult *render_result_from_bake(RenderEngine *engine, int x, int y,
   RenderPass *primitive_pass = render_layer_add_pass(rr, rl, 4, "BakePrimitive", "", "RGBA");
   RenderPass *differential_pass = render_layer_add_pass(rr, rl, 4, "BakeDifferential", "", "RGBA");
 
+  render_result_passes_allocated_ensure(rr);
+
   /* Fill render passes from bake pixel array, to be read by the render engine. */
   for (int ty = 0; ty < h; ty++) {
     size_t offset = ty * w * 4;
@@ -328,6 +330,7 @@ RenderResult *RE_engine_begin_result(
   /* can be NULL if we CLAMP the width or height to 0 */
   if (result) {
     render_result_clone_passes(re, result, viewname);
+    render_result_passes_allocated_ensure(result);
 
     RenderPart *pa;
 
@@ -400,6 +403,14 @@ void RE_engine_end_result(
     return;
   }
 
+  if (!re->result->passes_allocated) {
+    BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
+    if (!re->result->passes_allocated) {
+      render_result_passes_allocated_ensure(re->result);
+    }
+    BLI_rw_mutex_unlock(&re->resultmutex);
+  }
+
   /* merge. on break, don't merge in result for preview renders, looks nicer */
   if (!highlight) {
     /* for exr tile render, detect tiles that are done */
diff --git a/source/blender/render/intern/pipeline.c b/source/blender/render/intern/pipeline.c
index 479ad9209f0..9ef52b4bf41 100644
--- a/source/blender/render/intern/pipeline.c
+++ b/source/blender/render/intern/pipeline.c
@@ -354,6 +354,7 @@ RenderResult *RE_AcquireResultWrite(Render *re)
 {
   if (re) {
     BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
+    render_result_passes_allocated_ensure(re->result);
     return re->result;
   }
 
diff --git a/source/blender/render/intern/render_result.c b/source/blender/render/intern/render_result.c
index 091f5964291..c29ab342ed7 100644
--- a/source/blender/render/intern/render_result.c
+++ b/source/blender/render/intern/render_result.c
@@ -222,7 +222,6 @@ RenderPass *render_layer_add_pass(RenderResult *rr,
 {
   const int view_id = BLI_findstringindex(&rr->views, viewname, offsetof(RenderView, name));
   RenderPass *rpass = MEM_callocN(sizeof(RenderPass), name);
-  size_t rectsize = ((size_t)rr->rectx) * rr->recty * channels;
 
   rpass->channels = channels;
   rpass->rectx = rl->rectx;
@@ -249,33 +248,6 @@ RenderPass *render_layer_add_pass(RenderResult *rr,
     }
   }
 
-  /* Always allocate combined for display, in case of save buffers
-   * other passes are not allocated and only saved to the EXR file. */
-  if (rl->exrhandle == NULL || STREQ(rpass->name, RE_PASSNAME_COMBINED)) {
-    float *rect;
-    int x;
-
-    rpass->rect = MEM_callocN(sizeof(float) * rectsize, name);
-    if (rpass->rect == NULL) {
-      MEM_freeN(rpass);
-      return NULL;
-    }
-
-    if (STREQ(rpass->name, RE_PASSNAME_VECTOR)) {
-      /* initialize to max speed */
-      rect = rpass->rect;
-      for (x = rectsize - 1; x >= 0; x--) {
-        rect[x] = PASS_VECTOR_MAX;
-      }
-    }
-    else if (STREQ(rpass->name, RE_PASSNAME_Z)) {
-      rect = rpass->rect;
-      for (x = rectsize - 1; x >= 0; x--) {
-        rect[x] = 10e10;
-      }
-    }
-  }
-
   BLI_addtail(&rl->passes, rpass);
 
   return rpass;
@@ -316,6 +288,8 @@ RenderResult *render_result_new(
     rr->do_exr_tile = true;
   }
 
+  rr->passes_allocated = false;
+
   render_result_views_new(rr, &re->r);
 
   /* check renderdata for amount of layers */
@@ -484,6 +458,40 @@ RenderResult *render_result_new(
   return rr;
 }
 
+void render_result_passes_allocated_ensure(RenderResult *rr)
+{
+  LISTBASE_FOREACH (RenderLayer *, rl, &rr->layers) {
+    LISTBASE_FOREACH (RenderPass *, rp, &rl->passes) {
+      if (rl->exrhandle != NULL && !STREQ(rp->name, RE_PASSNAME_COMBINED)) {
+        continue;
+      }
+
+      if (rp->rect != NULL) {
+        continue;
+      }
+
+      const size_t rectsize = ((size_t)rr->rectx) * rr->recty * rp->channels;
+      rp->rect = MEM_callocN(sizeof(float) * rectsize, rp->name);
+
+      if (STREQ(rp->name, RE_PASSNAME_VECTOR)) {
+        /* initialize to max speed */
+        float *rect = rp->rect;
+        for (int x = rectsize - 1; x >= 0; x--) {
+          rect[x] = PASS_VECTOR_MAX;
+        }
+      }
+      else if (STREQ(rp->name, RE_PASSNAME_Z)) {
+        float *rect = rp->rect;
+        for (int x = rectsize - 1; x >= 0; x--) {
+          rect[x] = 10e10;
+        }
+      }
+    }
+  }
+
+  rr->passes_allocated = true;
+}
+
 void render_result_clone_passes(Render *re, RenderResult *rr, const char *viewname)
 {
   RenderLayer *rl;
@@ -1243,6 +1251,7 @@ void render_result_exr_file_end(Render *re, RenderEngine *engine)
   render_result_free_list(&re->fullresult, re->result);
   re->result = render_result_new(re, &re->disprect, RR_USE_MEM, RR_ALL_LAYERS, RR_ALL_VIEWS);
   re->result->stamp_data = stamp_data;
+  render_result_passes_allocated_ensure(re->result);
   BLI_rw_mutex_unlock(&re->resultmutex);
 
   LISTBASE_FOREACH (RenderLayer *, rl, &re->result->layers) {
diff --git a/source/blender/render/intern/render_result.h b/source/blender/render/intern/render_result.h
index 7732c113700..1fc64a4ea97 100644
--- a/source/blender/render/intern/render_result.h
+++ b/source/blender/render/intern/render_result.h
@@ -55,6 +55,8 @@ struct RenderResult *render_result_new(struct Render *re,
                                        const char *layername,
                                        const char *viewname);
 
+void render_result_passes_allocated_ensure(struct RenderResult *rr);
+
 struct RenderResult *render_result_new_from_exr(
     void *exrhandle, const char *colorspace, bool predivide, int rectx, int recty);