I need to control the influence of individual anchors. Actually, I need to have hard and soft anchors, and also I need to temporary deactivate some of them (so, influence= 0), and re-activate them later on.
Therefore, I think what I would need is the ability to control the influence of each anchor...
I don't think this would be a big change - I am pretty sure I can do it in an hour.
However, I don't want to use a customized version of Bullet, but would prefer sticking to the standard unmodified version (easier upgrade).
Would that be something that could be integrated into the main trunk ? I could eventually submit you the patch for that, if you agree with this idea...
cheers,
Greg
[EDIT]: below the DIFF for what I changed on my side. I would be glad if it were add into the main trunk
there is only one additional multiplication per anchor and per frame, I don't think this should make a big performance difference...
Code: Select all
Index: btSoftBody.cpp
===================================================================
--- btSoftBody.cpp (revision 2265)
+++ btSoftBody.cpp (working copy)
@@ -357,14 +357,14 @@
//
-void btSoftBody::appendAnchor(int node,btRigidBody* body, bool disableCollisionBetweenLinkedBodies)
+void btSoftBody::appendAnchor(int node,btRigidBody* body, bool disableCollisionBetweenLinkedBodies,btScalar influence)
{
btVector3 local = body->getWorldTransform().inverse()*m_nodes[node].m_x;
- appendAnchor(node,body,local,disableCollisionBetweenLinkedBodies);
+ appendAnchor(node,body,local,disableCollisionBetweenLinkedBodies,influence);
}
//
-void btSoftBody::appendAnchor(int node,btRigidBody* body, const btVector3& localPivot,bool disableCollisionBetweenLinkedBodies)
+void btSoftBody::appendAnchor(int node,btRigidBody* body, const btVector3& localPivot,bool disableCollisionBetweenLinkedBodies,btScalar influence)
{
if (disableCollisionBetweenLinkedBodies)
{
@@ -379,6 +379,7 @@
a.m_body = body;
a.m_local = localPivot;
a.m_node->m_battach = 1;
+ a.m_influence = influence;
m_anchors.push_back(a);
}
@@ -2765,7 +2766,7 @@
const btVector3 va=a.m_body->getVelocityInLocalPoint(a.m_c1)*dt;
const btVector3 vb=n.m_x-n.m_q;
const btVector3 vr=(va-vb)+(wa-n.m_x)*kAHR;
- const btVector3 impulse=a.m_c0*vr;
+ const btVector3 impulse=a.m_c0*vr*a.m_influence;
n.m_x+=impulse*a.m_c2;
a.m_body->applyImpulse(-impulse,a.m_c1);
}
Index: btSoftBody.h
===================================================================
--- btSoftBody.h (revision 2265)
+++ btSoftBody.h (working copy)
@@ -274,6 +274,7 @@
Node* m_node; // Node pointer
btVector3 m_local; // Anchor position in body space
btRigidBody* m_body; // Body
+ btScalar m_influence;
btMatrix3x3 m_c0; // Impulse matrix
btVector3 m_c1; // Relative anchor
btScalar m_c2; // ima*dt
@@ -745,8 +746,8 @@
/* Append anchor */
void appendAnchor( int node,
- btRigidBody* body, bool disableCollisionBetweenLinkedBodies=false);
- void appendAnchor(int node,btRigidBody* body, const btVector3& localPivot,bool disableCollisionBetweenLinkedBodies=false);
+ btRigidBody* body, bool disableCollisionBetweenLinkedBodies=false,btScalar influence = 1);
+ void appendAnchor(int node,btRigidBody* body, const btVector3& localPivot,bool disableCollisionBetweenLinkedBodies=false,btScalar influence = 1);
/* Append linear joint */
void appendLinearJoint(const LJoint::Specs& specs,Cluster* body0,Body body1);
void appendLinearJoint(const LJoint::Specs& specs,Body body=Body());
