Cycles microdisplacement: Improved automatic bump mapping

Object coordinates can now be used in the displacement shader and will give
correct results, where as before bump mapping was calculated from the displace
positions and resulted in incorrect shading.

This works by evaluating the shader in two parts, first bump then surface, and
setting the shader state to match what it would be if the surface was
undisplaced for the bump shader evaluation. Currently only `P` is set as if
undisplaced, but other shader variables could be set as well, such as `I` or
`time`. Since these aren't set to anything meaningful for displacement I left
them out of this patch, we can decide what to do with them separately.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D2156

1 files changed, 2 insertions, 21 deletions

diff --git a/intern/cycles/render/graph.cpp b/intern/cycles/render/graph.cpp
index 6e795ef896a..57256ceecd3 100644
--- a/intern/cycles/render/graph.cpp
+++ b/intern/cycles/render/graph.cpp
@@ -856,27 +856,8 @@ void ShaderGraph::bump_from_displacement()
 	/* connect the bump out to the set normal in: */
 	connect(bump->output("Normal"), set_normal->input("Direction"));
 
-	/* connect bump output to normal input nodes that aren't set yet. actually
-	 * this will only set the normal input to the geometry node that we created
-	 * and connected to all other normal inputs already. */
-	foreach(ShaderNode *node, nodes) {
-		/* Don't connect normal to the bump node we're coming from,
-		 * otherwise it'll be a cycle in graph.
-		 */
-		if(node == bump) {
-			continue;
-		}
-		foreach(ShaderInput *input, node->inputs) {
-			if(!input->link && (input->flags() & SocketType::LINK_NORMAL))
-				connect(set_normal->output("Normal"), input);
-		}
-	}
-
-	/* for displacement bump, clear the normal input in case the above loop
-	 * connected the setnormal out to the bump normalin */
-	ShaderInput *bump_normal_in = bump->input("Normal");
-	if(bump_normal_in)
-		bump_normal_in->link = NULL;
+	/* connect to output node */
+	connect(set_normal->output("Normal"), output()->input("Normal"));
 
 	/* finally, add the copied nodes to the graph. we can't do this earlier
 	 * because we would create dependency cycles in the above loop */