- when not F10->"Ray" option is set, materials with "Ray Transp" will

render solid now (no alpha).
- This gives nicer previews, but also makes envmaps look better, since
  environment maps are rendered without raytracing
- I decided not to raytrace envmaps mainly because of speed... if you use
  environment maps you want something quick... otherwise just use ray_mir
  material here!

source/blender/render/intern/source/envmap.c

@@ -502,10 +502,13 @@ void render_envmap(EnvMap *env)
 void make_envmaps()
 {
 	Tex *tex;
-	int do_init= 0, depth= 0;
+	int do_init= 0, depth= 0, trace;
 	
 	if (!(R.r.mode & R_ENVMAP)) return;
-
+	
+	/* we dont raytrace, disabling the flag will cause ray_transp render solid */
+	trace= (R.r.mode & R_RAYTRACE);
+	R.r.mode &= ~R_RAYTRACE;
 
 	/* 5 = hardcoded max recursion level */
 	while(depth<5) {
@@ -556,6 +559,9 @@ void make_envmaps()
 		RE_local_clear_render_display(R.win);
 		allqueue(REDRAWBUTSSHADING, 0);			// bad!
 	}	
+	// restore
+	R.r.mode |= trace;
+
 }
 
 /* ------------------------------------------------------------------------- */

source/blender/render/intern/source/renderPreAndPost.c

@@ -81,6 +81,7 @@ void prepareScene()
 
 		/* octree */
 		if(R.r.mode & R_RAYTRACE) makeoctree();
+
 	}
 }
 

source/blender/render/intern/source/rendercore.c

@@ -2475,6 +2475,10 @@ void *shadepixel(float x, float y, int vlaknr, int mask, float *col)
 				ray_trace(&shi, &shr, mask);
 			}
 		}
+		else {
+			// doesnt look 'correct', but is better for preview, plus envmaps dont raytrace this
+			if(shi.mat->mode & MA_RAYTRANSP) shr.alpha= 1.0;
+		}
 		
 		VecAddf(col, shr.diff, shr.spec);