Unexpected line while using Anarienderer

OVITO
1

Hi,

For easier visualization of my triclinic system, I set the camera direction along cell vector and it works. However, I noticed that when using Anari render along the c-axis, additional black lines extending along the box cell appear. This issue doesn’t occur in other directions or when switching to OpenGL. I’m not certain what’s causing this, so I’m reporting it here. Below is a portion of the code and the animation I rendered:

    vp = Viewport()
    vp.type = Viewport.Type.Ortho
    camera_dic = {
        'xyz': [3, 2],  # ortho
        'a': [0, 2],    # front
        'b': [1, 2],    # left
        'c': [2, 0],    # top
    }
    camera = camera_dic[direction]
    dir = camera[0]
    up = camera[1]
    vp.camera_dir = data.cell_[:, dir]
    vp.camera_up = data.cell_[:, up]
    vp.zoom_all()

 
    # Attach overlay to a newly created viewport.
    vp.overlays.append(tripod)
    vp.overlays.append(overlay)
    vp.render_anim(**render_args)

Anari along c
animation_c_0_1000_10_20_anari

OpenGL along c
animation_c_0_1000_10_20_opengl

2

My operating system is Linux. To display fonts, I set QT_DEBUG_BACKINGSTORE=1 . However, I have tested and confirmed that QT_DEBUG_BACKINGSTORE and xvfb-run do not affect whether this black line appears or not.

3

Could you provide a snapshot file from your simulation? I would like to reproduce the issue and this probably requires the precise simulation cell geometry.

4

I can’t upload original snapshot file due to new user. So I extract several waters as below. It is .gro format

waters
 9
    1SOL     OW    1   5.505   9.569   2.926 -0.3533  0.3722 -0.2657
    1SOL    HW1    2   5.524   9.590   3.017  1.2382 -1.6602 -0.1022
    1SOL    HW2    3   5.463   9.483   2.930  0.3484 -0.0302 -1.5018
    2SOL     OW    4   5.790   9.519   3.177 -0.2792 -0.2234 -0.3107
    2SOL    HW1    5   5.881   9.536   3.204 -0.3858 -0.1990  0.0393
    2SOL    HW2    6   5.737   9.566   3.242 -0.5364 -0.0222 -0.6693
    3SOL     OW    7   5.950   9.966   2.687 -0.1916  0.5178  0.4820
    3SOL    HW1    8   5.971   9.875   2.708 -1.6153  0.0861  0.1143
    3SOL    HW2    9   5.925  10.005   2.771  0.3686  0.5572  0.6311
   6.00100  10.44072   3.37442   0.00000   0.00000   0.00000   0.00000   0.00000   4.98051

Here is my test:
animation_c_0_1000_10_20_anari

5

By the way, I found that the lines disappeared if switching to Viewport.Type.Perspective.

animation_c_0_1000_10_20_anari

6

Thanks. I can reproduce the problem on my system.

This visual artifact seems to be a bug in the cylinder rendering routine of the VisRTX renderer, which only shows under rare circumstances (very specific cylinder/camera relative orientation). I’ll have to isolate it and report it to the NVIDIA developers, so they can fix it in the VisRTX code.