modify cloth position particle after cloth is on GPU

[rossetti73]

Hi ,
i try modify SnippetPDBCloth to move some position particle after cloth is on gpu.
I try modify in stepPhysics like this:

void stepPhysics(bool /*interactive*/)
{
	if (gMovePos)
	{		
		PxCudaContextManager* cudaContexManager = gScene->getCudaContextManager();
		cudaContexManager->acquireContext();
		PxCudaContext* cudaContext = cudaContexManager->getCudaContext();
		PxParticleClothBuffer* userBuffer = gClothBuffer;
		PxVec4* positions = userBuffer->getPositionInvMasses();
		const PxU32 numParticles1 = userBuffer->getNbActiveParticles();
		float* b = (float*)malloc(numParticles1 * sizeof(PxVec4));
		cudaContext->memcpyDtoH(b, CUdeviceptr(positions), sizeof(PxVec4) * numParticles1);
		PxVec4* positionsH = (PxVec4*)(b);
		positionsH[0] = PxVec4(-6.25, 8, -6.25, 0);
		cudaContext->memcpyHtoD(CUdeviceptr(positions), positionsH, numParticles1 * sizeof(PxVec4));
		free(b);
		cudaContexManager->releaseContext();
	}
	if (gIsRunning)
	{
		const PxReal dt = 1.0f / 60.0f;

		bool rotatingSphere = true;
		if (rotatingSphere)
		{
			const PxReal speed = 2.0f;
			PxTransform pose = sphere->getGlobalPose();			
			sphere->setKinematicTarget(PxTransform(pose.p, PxQuat(PxCos(simTime*speed), PxVec3(0,1,0))));
		}

		gScene->simulate(dt);
		gScene->fetchResults(true);
		gScene->fetchResultsParticleSystem();
		simTime += dt;
	}
}

I add modify position 0 before made step of simulation but seams not working .
gMovePos became true when i click key 'Q'.
Any suggestion ?

Thanks bye .

[adenzler-nvidia]

Hi!
You're missing a call to userBuffer->raiseFlags(PxParticleBufferFlag::eUPDATE_POSITION) to tell the particle system that the positions have been updated. See the Particle Buffers section in the user guide.

[rossetti73]

Thanks very much !!