[SOLVED] Geometry Shader question

zissis · March 12, 2019, 6:46pm

As the title states, do we have a hidden geometry shader pipeline in JME? The reason why I ask is I want to create a geometry shader that allows me to transition a planet from a sphere in stace to mountainous terrain as I gen closer. I also want to create an exploding ship effect with debris.

jayfella · March 12, 2019, 8:47pm

github.com

jMonkeyEngine/jmonkeyengine/blob/master/jme3-examples/src/main/java/jme3test/material/TestGeometryShader.java

package jme3test.material;

import com.jme3.app.SimpleApplication;
import com.jme3.bounding.BoundingBox;
import com.jme3.material.Material;
import com.jme3.math.Vector3f;
import com.jme3.scene.Geometry;
import com.jme3.scene.Mesh;
import com.jme3.scene.VertexBuffer;
import com.jme3.scene.shape.Sphere;
import com.jme3.system.AppSettings;
import com.jme3.util.BufferUtils;

/**
 * Created by michael on 23.02.15.
 */
public class TestGeometryShader extends SimpleApplication {
    @Override
    public void simpleInitApp() {
        Mesh mesh = new Mesh();

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And probably this

github.com

jMonkeyEngine/jmonkeyengine/blob/d57c362ec3b510c1ba6356f719efa3b1576b95c6/jme3-testdata/src/main/resources/Materials/Tess/SimpleTess.j3md

MaterialDef SimpleGeom {

    MaterialParameters {
        Texture2D NormalDisplacementMap
        Int TessellationFactor
    }

     Technique {
        VertexShader GLSL400:   Materials/Tess/SimpleTess.vert
        TessellationEvaluationShader GLSL400:   Materials/Tess/SimpleTess.tseval
        TessellationControlShader GLSL400:   Materials/Tess/SimpleTess.tsctrl
        FragmentShader GLSL400: Materials/Tess/SimpleTess.frag

        WorldParameters {
            WorldViewProjectionMatrix
        }
    }

}

thetoucher · March 12, 2019, 9:12pm

Yes we have a geometry shader, I used it here :

Sounds like you need a tessellation shader, not a geometry one. Geo shaders add limited amounts of extra geometry, tessellation adds extra detail.

Edit: going from planet to surface requires a mesh LOD solution, not a shader solution.

zissis · March 12, 2019, 10:05pm

OK I am an idiot. I should have looked at the test classes. Now I feed like a noob. Thank you for pointing out my ignorance lol

thetoucher · March 12, 2019, 10:06pm

They’ve been working on this thing called Google for a while now, I hear it’s pretty good at helping in situations like this.

pspeed · March 12, 2019, 10:10pm

That’s crazy talk.

zissis · March 12, 2019, 10:14pm

I deserve that one It’s rare that I get a brain fart but when I do … it’s epic!

thetoucher · March 12, 2019, 10:38pm

This one was more of a public shart