slow heightfield in Physx 3.4.1

I’m creating a heightfield, as per the sample code and documentation. I’m surprised at how poorly it’s performing and I’m wondering if I’m doing something wrong or if what I am seeing is expected.

The height field is 1000*1000 units, it’s the only actor in the physx scene and in release I’m only getting about 10FPS, in debug it’s less than 1. If I cook the heightfield and create the actor, but don’t add it to the scene I get 300FPS so I think it must be because it’s in the scene. I don’t understand why performance is so poor, I don’t have any other actors in the scene so there is is literally nothing interacting with it. I’m sure of this because I’ve checked in the PVD and the only thing in the scene is the height map.

Does anyone have any experience of this? I haven’t bothered including my code because it is virtually the same as the code in the documentation. I note that the example in the samples is only 128 square, but that seems unrealistically small and not representative of what one would expect with the current crop of open world game height maps.

Any help is most appreciated.


Tony Oakden

Hmmm. Literally seconds after I posted this I noticed this line in the code which sets up my scene:

m_scene->setVisualizationParameter(physx::PxVisualizationParameter::eSCALE, m_initialDebugRender ? m_initialDebugRender : 0.0f);

I commented it out and suddenly I’m getting 500 FPS in release.

I’m a bit confused as to why this would be?