public void setDepthTest(boolean depthTest) {
        applyDepthTest = true;
        this.depthTest = depthTest;
        cachedHashCode = -1;
    }
Enable depth testing.

<p>When depth testing is enabled, a pixel must pass the depth test
before it is written to the color buffer.
The input pixel's depth value must be less than or equal than
the value already in the depth buffer to pass the depth test.

@param depthTest Enable or disable depth testing.
jme3-core/src/main/java/com/jme3/material/RenderState.java