filtered scenes are squeezed by resizable windows

I’ve been converting apps to use resizable windows. Mostly this just involves invoking AppSettings.setResizable() and adjusting the GUI layout each time the window gets resized.

I’ve encountered an issue involving filters in resizable windows, and I believe it’s a bug in the Engine. When I resize a window to a new aspect ratio, the rendered scene gets squashed to “fit” the new aspect ratio. This only happens when there are filters. In an unfiltered scene, no squashing occurs.

Here’s a simple testcase based on TestCartoonEdge:

package jme3test.post;

import com.jme3.app.SimpleApplication;
import com.jme3.light.DirectionalLight;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Quaternion;
import com.jme3.math.Vector3f;
import com.jme3.post.FilterPostProcessor;
import com.jme3.post.filters.CartoonEdgeFilter;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.Spatial.CullHint;
import com.jme3.system.AppSettings;
import com.jme3.texture.Texture;

public class TestIssueXXXX extends SimpleApplication {

    private FilterPostProcessor fpp;

    public static void main(String[] args) {
        AppSettings s = new AppSettings(true);
        s.setResizable(true);
        TestIssueXXXX app = new TestIssueXXXX();
        app.setSettings(s);
        app.start();
    }

    private void setupFilters() {
        fpp = new FilterPostProcessor(assetManager);
        int numSamples = getContext().getSettings().getSamples();
        if (numSamples > 0) {
            fpp.setNumSamples(numSamples);
        }
        CartoonEdgeFilter toon = new CartoonEdgeFilter();
        toon.setEdgeColor(ColorRGBA.Yellow);
        fpp.addFilter(toon);
        viewPort.addProcessor(fpp);
    }

    private void makeToonish(Spatial spatial) {
        if (spatial instanceof Node) {
            Node n = (Node) spatial;
            for (Spatial child : n.getChildren()) {
                makeToonish(child);
            }
        } else if (spatial instanceof Geometry) {
            Geometry g = (Geometry) spatial;
            Material m = g.getMaterial();
            if (m.getMaterialDef().getMaterialParam("UseMaterialColors") != null) {
                Texture t = assetManager.loadTexture("Textures/ColorRamp/toon.png");
                m.setTexture("ColorRamp", t);
                m.setBoolean("UseMaterialColors", true);
                m.setColor("Specular", ColorRGBA.Black);
                m.setColor("Diffuse", ColorRGBA.White);
                m.setBoolean("VertexLighting", true);
            }
        }
    }

    private void setupLighting() {
        DirectionalLight dl = new DirectionalLight();
        dl.setDirection(new Vector3f(-1, -1, 1).normalizeLocal());
        dl.setColor(new ColorRGBA(2, 2, 2, 1));
        rootNode.addLight(dl);
    }

    private void setupModel() {
        Spatial model = assetManager.loadModel("Models/MonkeyHead/MonkeyHead.mesh.xml");
        makeToonish(model);
        rootNode.attachChild(model);
    }

    @Override
    public void simpleInitApp() {
        viewPort.setBackgroundColor(ColorRGBA.Gray);
        flyCam.setDragToRotate(true);
        setupLighting();
        setupModel();
        setupFilters();
    }
}

[stephengold]

Is it reproducible with older JME versions too?

Yes. All the way back to 3.1.0-stable .

[stephengold]

Here’s an example of a squashed scene: