Re: Glitch in simple pore constraint visualization with openGL

[Patrick Kreissl]

Hi Le,

thank you for your Email.

What you observe is a known problem on some hardware including Mac.
The OpenGl-visualizer uses clip planes to cap objects at the box boundaries. Also, some Constraint-visualizations, such as the SimplePore, require additional clip planes to render the object. In general it is possible to request the additionally needed clip planes from OpenGL. This works on most Linux machines. However, unfortunately, on Mac there is an upper limit for the clip planes allowed (6). Shapes that would need additional clipping will in this case not be clipped on one face of the box.
I suppose that choosing the simple pore in x direction, you are lucky as so far as that the pore is not clipped on one of the boundaries that are not crossed by the Shape, so visualization seemingly works -- I imagine that having an additional ShapeBasedConstraint that crosses one of these box faces would lead to a similar 'glitch'.

What happened when not adding particles is not clear to me, however.
On my machine that works quite fine, but I am a Linux user...

Pleate note that the online visualizer is not meant to produce high quality renderings, but rather to help you debug your system. Still, I guess you can mitigate the issue by staying with the working choice for the direction of the SimplePore or, if possible for you, switch to a Linux machine for online visualized debugging. For high quality rendering, you could consider writing out *.vtk files for your simulation and animate the data using visualization software such as ParaView.

Best wishes,
Patrick Kreissl

On 10/24/21 1:44 PM, Le Qiao wrote:

Hi,

Recently I encounter a glitch while using espresso 4.1 and dev on my M1 Mac (python 3.9.1), not sure if you have the same issue or just me.  This happens when you place the the simple pore constraint in y- or z-direction, the wall is oddly extended in one direction for some reason, as shown below.  But it is alright when you change this to x-direction (axis=[1.0, 0.0, 0.0]). 

Also, when you add no particle, the visualization of the simplepore constraints is very strange, see the third figure.

I tested this with the script “visualization_constraints.py” in the SAMPLES directory.

1. Simple pore placed in y-and z-direction

2. placed in x direction

3. simple pore without particles

Cheers

Le