Gazebo 8 Heightmap objects clipping through collision

[osrf-migration]

Original report (archived issue) by Rasmus Iila (Bitbucket: Raskkii).

The original report had attachments: slope_example.tar.gz

---

I was asked to ticket an issue to follow up on my question here: http://answers.gazebosim.org/question/18088/gazebo-8-heightmap-objects-clipping-through-collision/

As you can see, the heightmap seems to have an issue with objects clipping through the edge of the slope.

Now, I've done some additional testing regarding this issue. I've created a simple example that illustrates the problem, which can be found in the atttachments. I've also included a README file in the attachments to provide instructions on how to run the example.

I've tested the issue with spheres of different sizes and positions.
I've concluded, that a sphere with a radius of 0.38 m or below falls through, while a sphere with a radius of 0.39 m or above does not fall through.
When the sphere has a radius of 0.38 m, the window of falling through the collision is about 0.04 m (on x-axis on my example). The window does not seem to vary when moving the spheres along the y-axis.
However, interestingly, when reducing the radiuses of the spheres, the window of falling through also decreases. For example, a sphere with a radius of 0.05 m has a window of only about 0.002 m.
So to conclude, the window increases as the sphere radius increases, up until a radius of 0.39 m at which point the sphere does not fall through any more (though a part of it still clips through so the sphere starts rolling sideways even when it shouldn't).

I've set the priority as blocker as this bug prevents us from working with wheeled vehicles on slopy surfaces (such as driving up a ramp). The wheel radius of our vehicle is about 0.2 m so right about in the middle as far as the window of falling through goes.

I've also added two screenshots in the attachments of what happens when I unpause.

[osrf-migration]

Original comment by Ian Chen (Bitbucket: Ian Chen, GitHub: iche033).

---

• changed state from "new" to "duplicate"

Duplicate of #245.

[osrf-migration]

Original comment by Ian Chen (Bitbucket: Ian Chen, GitHub: iche033).

---

workaround for now is to use a higher resolution heightmap file

[osrf-migration]

Original comment by Rasmus Iila (Bitbucket: Raskkii).

---

I have tried with resolutions up to 1025x1025 and the clipping still happens.