[SOLVED] Mesh + Material with Lighting.j3md throws error

oxplay2 · August 29, 2019, 10:05am

Lighting.j3md require Proper normal (vertex/face direction) in Mesh. it is you need to fill this:

mesh.setBuffer(VertexBuffer.Type.Normal, 3, nb);

for full quad for example you can fill it like:

nb.put(normalDirection.x).put(normalDirection.y).put(normalDirection.z);
nb.put(normalDirection.x).put(normalDirection.y).put(normalDirection.z);
nb.put(normalDirection.x).put(normalDirection.y).put(normalDirection.z);
nb.put(normalDirection.x).put(normalDirection.y).put(normalDirection.z);

Also it require Light so it will not be just black and Front of face will be lit. it can be done with:

rootNode.addLight(al) //ambient light - overall light not depends on normals, but normals you need to see front faces
rootNode.addLight(dl) //directional light - it depends on normals from your mesh

As i know this 2 things(light/normals) is required for your Lighting.j3md to not be “black”(not lit).

Unshaded do not need light/normals. PBR also need lightProbe to make metallic work. As you can see each material can have some “requirements”.

Anyway imo TestCase is always easiest way to solve.

pspeed · August 29, 2019, 8:30pm

To put this as plainly and bluntly as possible.

Lighting = how much is this face pointing at the light.
“face pointing” = normal

Lighting requires normals.

If your mesh doesn’t have a normal buffer, no lighting for you… as the surfaces are never pointing to the light.

mitm · August 30, 2019, 1:40am

I think hes confused as to why the Box works when his is not and hes using the same material even though you guys are telling him the answer.

github.com

jMonkeyEngine/jmonkeyengine/blob/d57c362ec3b510c1ba6356f719efa3b1576b95c6/jme3-core/src/main/java/com/jme3/scene/shape/Box.java#L58


private static final short[] GEOMETRY_INDICES_DATA = {
     2,  1,  0,  3,  2,  0, // back
     6,  5,  4,  7,  6,  4, // right
    10,  9,  8, 11, 10,  8, // front
    14, 13, 12, 15, 14, 12, // left
    18, 17, 16, 19, 18, 16, // top
    22, 21, 20, 23, 22, 20  // bottom
};
private static final float[] GEOMETRY_NORMALS_DATA = {
    0,  0, -1,  0,  0, -1,  0,  0, -1,  0,  0, -1, // back
    1,  0,  0,  1,  0,  0,  1,  0,  0,  1,  0,  0, // right
    0,  0,  1,  0,  0,  1,  0,  0,  1,  0,  0,  1, // front
   -1,  0,  0, -1,  0,  0, -1,  0,  0, -1,  0,  0, // left
    0,  1,  0,  0,  1,  0,  0,  1,  0,  0,  1,  0, // top
    0, -1,  0,  0, -1,  0,  0, -1,  0,  0, -1,  0  // bottom
};
private static final float[] GEOMETRY_TEXTURE_DATA = {
    1, 0, 0, 0, 0, 1, 1, 1, // back

Edmund · August 30, 2019, 8:56am

Now i understand that I need a VertexBuffer for the normals. Everything works fine now. Thank you all very much!!