Hello,

So I'm trying to create a lighting system on my XNA game, and I found a great shader on the internet:

http://pastebin.com/Y3Lvuwwk

But the problem is that my models have multiple textures, and this shader accept only one texture, so my models are finally drawn with one model on all their meshes.

Here's how I apply the effect on my model:

        public void SetModelEffect(Effect effect, bool CopyEffect)
        {
            foreach (ModelMesh mesh in _model.Meshes)
                foreach (ModelMeshPart part in mesh.MeshParts)
                {
                    Effect toSet = effect;

                    // Copy the effect if necessary
                    if (CopyEffect)
                        toSet = effect.Clone();

                    MeshTag tag = ((MeshTag)part.Tag);

                    // If this ModelMeshPart has a texture, set it to the effect
                    if (tag.Texture != null)
                    {
                        setEffectParameter(toSet, "BasicTexture", tag.Texture);
                        setEffectParameter(toSet, "TextureEnabled", true);
                    }
                    else
                        setEffectParameter(toSet, "TextureEnabled", false);

                    // Set our remaining parameters to the effect
                    setEffectParameter(toSet, "DiffuseColor", tag.Color);
                    setEffectParameter(toSet, "SpecularPower", tag.SpecularPower);

                    part.Effect = toSet;
                }
        } 

And here is how I draw my models with all their textures when the effect is not applied:

            foreach (ModelMesh mesh in _model.Meshes)
            {
                Matrix localWorld = _modelTransforms[mesh.ParentBone.Index] * world;
                foreach (ModelMeshPart meshPart in mesh.MeshParts)
                {
                    Effect effect = meshPart.Effect;


                    if (effect is BasicEffect)
                    {
                        BasicEffect bEffect = (BasicEffect)effect;

                        bEffect.Texture = _textures[newName];


                        bEffect.World = localWorld;
                        bEffect.View = view;
                        bEffect.Projection = projection;
                         ...

I took a second look on the code and indeed it should work, because different instances of the effect are applied on every meshparts.

I tried to debug it and it seems the problem is actually coming from the fact that when I generate tags, all ModelMeshPart have the same texture...

Here's my function generateTags, which create a MeshTag used by SetModelEffect:

private void generateTags()
        {
            foreach (ModelMesh mesh in _model.Meshes)
                foreach (ModelMeshPart part in mesh.MeshParts)
                    if (part.Effect is BasicEffect)
                    {
                        BasicEffect effect = (BasicEffect)part.Effect;
                        MeshTag tag = new MeshTag(effect.DiffuseColor,
                            effect.Texture, effect.SpecularPower);
                        part.Tag = tag;
                    }
        }

So on my LoadContent I added this:

foreach (ModelMesh mesh in _model.Meshes)
                    foreach (ModelMeshPart part in mesh.MeshParts)
                        if (part.Effect is BasicEffect)
                        {
                            BasicEffect effect = (BasicEffect)part.Effect;
                            string newName = mesh.Name.Split('_')[0];
                            effect.Texture = _textures[newName];
                        }

But it doesn't work; I don't get it...

EDIT:

So I got something working.

In my generateTags function, I had to reload tag.Texture with my texture dictionnary I've been using when loading the content. That works, but I still don't understand why does my tags are all the same... ?

Thx anyway for putting my on the correct way, once again!