Pointcache refresh part 2

* Based on what happens during simulation the cache is marked (also in cache panel, this could possibly be extended to 3d view as well) as:
	- exact (not marked)
	- outdated (simulation is not done completely with current settings)
	- non-exact (frames were skipped during simulation)

* The parameter "cache step" effects the number of frames between saved cache frames.
	- This can save a lot of memory (or disk space) if absolutely frame accurate simulation is not required.
	- Speeds up the "quick caching" very much.
	- Frames between cached frames are interpolated from the cached frames.
	- Current default value of 10 frames works nicely with up/down-arrows (skip 10 frames forwards/backwards on timeline), but can be changed if wanted.

* The caching can work in normal or "quick" mode:
	[Normal cache]
	- Basic: Calculate what even happens (settings change, big frame steps etc.) and cache results, if possible try to use "cache step" when saving cache frames.
	- Becomes non-exact: After larger than 1 frame steps.
	- Becomes outdated: After any change effecting the simulation other than frame steps.
	- Pros/cons: Freedom of doing anything and playing with particles, but exact results have to calculated from the beginning.

	[Quick cache]
	- Basic: Calculate simulation up to current frame automatically on changes with cache step sized jumps in simulation. With multiple "quick cached" simulations the smallest cache step is used.
	- Becomes non-exact: Always from frame 1 (unless cache step = 1).
	- Becomes outdated: Never.
	- Pros/cons: Not very accurate, but super fast!
	- Todo: Transform of any animated (non-autokeyed) object is locked! Probably needs some tinkering with anim sys overrides.

* The simulation can be run forwards or backwards even if it's cache is outdated or non-exact, the following rules apply in these situations:
	- step forwards (to unknown) -> simulate from last exact frame, store result
	- step backwards (to known) -> result is interpolated from existing frames, store result, clear cache forwards if current frame is after last exact frame

* "Calculate to current frame" runs the simulation from start to current frame with a frame steps of 1.
	- Baking does the same, but runs the simulation all the way to the end of simulation.
	- Rendering does this automatically if the simulation is outdated of non-exact, so all rendered simulations will always be updated and exact.
	
* Every cache panel also holds buttons to "Bake all dynamics", "Free all dynamics" and "Update all dynamics to current frame".

* Cloth simulation supports the new cache too.

1 files changed, 8 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/implicit.c b/source/blender/blenkernel/intern/implicit.c
index 40c98c1d9cc..fc5213d5532 100644
--- a/source/blender/blenkernel/intern/implicit.c
+++ b/source/blender/blenkernel/intern/implicit.c
@@ -1600,6 +1600,10 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 		
 		if(clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_ENABLED)
 		{
+			float temp = clmd->sim_parms->stepsPerFrame;
+			/* not too nice hack, but collisions need this correction -jahka */
+			clmd->sim_parms->stepsPerFrame /= clmd->sim_parms->timescale;
+
 			// collisions 
 			// itstart();
 			
@@ -1614,7 +1618,7 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 			
 			// call collision function
 			// TODO: check if "step" or "step+dt" is correct - dg
-			result = cloth_bvh_objcollision(ob, clmd, step, dt);
+			result = cloth_bvh_objcollision(ob, clmd, step/clmd->sim_parms->timescale, dt/clmd->sim_parms->timescale);
 			
 			// correct velocity again, just to be sure we had to change it due to adaptive collisions
 			for(i = 0; i < numverts; i++)
@@ -1637,6 +1641,9 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 				}
 			}
 			
+			/* restore original stepsPerFrame */
+			clmd->sim_parms->stepsPerFrame = temp;
+			
 			// X = Xnew;
 			cp_lfvector(id->X, id->Xnew, numverts);
 			
@@ -1654,7 +1661,6 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 				
 				simulate_implicit_euler(id->Vnew, id->X, id->V, id->F, id->dFdV, id->dFdX, dt / 2.0f, id->A, id->B, id->dV, id->S, id->z, id->olddV, id->P, id->Pinv, id->M, id->bigI);
 			}
-			
 		}
 		else
 		{