Cloth refactor: Remove goal springs and some other cleanup

This removes the goal springs, in favor of simply calculating the goal forces on the vertices directly. The vertices already store all the necessary data for the goal forces, thus the springs were redundant, and just defined both ends as being the same vertex.

The main advantage of removing the goal springs, is an increase in flexibility, allowing us to much more nicely do some neat dynamic stuff with the goals/pins, such as animated vertex weights. But this also has the advantage of simpler code, and a slightly reduced memory footprint.

This also removes the `f`, `dfdx` and `dfdv` fields from the `ClothSpring` struct, as that data is only used by the solver, and is re-computed on each step, and thus does not need to be stored throughout the simulation.

Reviewers: sergey

Reviewed By: sergey

Tags: #physics

Differential Revision: https://developer.blender.org/D2514

1 files changed, 0 insertions, 37 deletions

diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index 28ef3f6f248..ee0fde1ea61 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -869,12 +869,6 @@ static int cloth_from_object(Object *ob, ClothModifierData *clmd, DerivedMesh *d
 		return 0;
 	}
 	
-	for ( i = 0; i < dm->getNumVerts(dm); i++) {
-		if ((!(cloth->verts[i].flags & CLOTH_VERT_FLAG_PINNED)) && (cloth->verts[i].goal > ALMOST_ZERO)) {
-			cloth_add_spring (clmd, i, i, 0.0, CLOTH_SPRING_TYPE_GOAL);
-		}
-	}
-	
 	// init our solver
 	BPH_cloth_solver_init(ob, clmd);
 	
@@ -944,37 +938,6 @@ BLI_INLINE void spring_verts_ordered_set(ClothSpring *spring, int v0, int v1)
 	}
 }
 
-// be careful: implicit solver has to be resettet when using this one!
-// --> only for implicit handling of this spring!
-int cloth_add_spring(ClothModifierData *clmd, unsigned int indexA, unsigned int indexB, float restlength, int spring_type)
-{
-	Cloth *cloth = clmd->clothObject;
-	ClothSpring *spring = NULL;
-	
-	if (cloth) {
-		// TODO: look if this spring is already there
-		
-		spring = (ClothSpring *)MEM_callocN ( sizeof ( ClothSpring ), "cloth spring" );
-		
-		if (!spring)
-			return 0;
-		
-		spring->ij = indexA;
-		spring->kl = indexB;
-		spring->restlen =  restlength;
-		spring->type = spring_type;
-		spring->flags = 0;
-		spring->stiffness = 0;
-		
-		cloth->numsprings++;
-	
-		BLI_linklist_prepend ( &cloth->springs, spring );
-		
-		return 1;
-	}
-	return 0;
-}
-
 static void cloth_free_edgelist(LinkNodePair *edgelist, unsigned int mvert_num)
 {
 	if (edgelist) {