Z-fighting problems reappear between species

[AlexisDrogoul]

(related to #2209)

Steps to reproduce

1. Open the model Ant Foraging (Complex).gaml

2.Create a new display in one of the experiments, equivalent to the 2D display minus the overlay, i.e.

        display Ants3D type: opengl {
            image '../images/soil.jpg' position: { 0.05, 0.05 } size: { 0.9, 0.9 };
            agents "agents" transparency: 0.7 position: { 0.05, 0.05 } size: { 0.9, 0.9 } value: (ant_grid as list) where ((each.food > 0) or (each.road > 0) or (each.is_nest)) ;
            species ant position: { 0.05, 0.05 } size: { 0.9, 0.9 } aspect: icon;                   
        }

3. Launch the experiment containing this display.

Expected behavior

When displayed, the ants should be on top of the grid cells.

Actual behavior

The cells and the ants are mixed without too much logic. See snapshot. Some ants are below some cells, while others are above.

Workaround

A (not so satisfying) workaround is to provide some bit of elevation to the ant layer, e.g. species ant position: { 0.05, 0.05, 0.01 }.

System and version

GAMA 1.7 Git, Mac OSX 10.12.5

[agrignard]

Not a good news. What has been changed in opengl? Did we update any new library that might have introduces this regression?

[AlexisDrogoul]

Should be fixed by https://github.com/gama-platform/gama/commit/9dc3ecdac294595cb7c475e745672a12ac0b0768