How are you calling CombineMeshes now | Official Unity Discord | Page 1

hidden smelt Sep 1, 2023, 3:34 AM

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So this is my current code:

public static void Run2(in Mesh prefab, IMeshDeformPath path, out Mesh result)
{
    result = new Mesh();
    result.name = prefab.name;

    var verts = prefab.vertices;
    var newVerts = new Vector3[verts.Length];
    List<CombineInstance> combines = new List<CombineInstance>();

    for (int i = 0; i < path.Length; i++)
    {
        //new mesh for each step along the path
        var m = Object.Instantiate(prefab);

        //deform to conform to the path
        for (var v = 0; v < verts.Length; v++)
            newVerts[v] = Update(verts[v], i, path);

        //set the vertices
        m.vertices = newVerts;

        //add its submesh data to the list
        for (int s = 0; s < prefab.subMeshCount; s++)
            combines.Add(new CombineInstance() { mesh = m, subMeshIndex = s });
    }

    result.CombineMeshes(combines.ToArray(), false, false, false);
    result.RecalculateBounds();
    result.RecalculateNormals();
}

tranquil lotus Sep 1, 2023, 3:35 AM

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So from my understanding you want to call CombineMeshes three times

hidden smelt Sep 1, 2023, 3:35 AM

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or one per submesh plus the final combine?

tranquil lotus Sep 1, 2023, 3:35 AM

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Yes

hidden smelt Sep 1, 2023, 3:35 AM

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hm i see

tranquil lotus Sep 1, 2023, 3:36 AM

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So first two call with merging

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And last call without merging

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I assume performance is not big issue here

hidden smelt Sep 1, 2023, 3:37 AM

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well it is for run time

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but the vert manipulation is in a job system

tranquil lotus Sep 1, 2023, 3:37 AM

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I guess you might want to improve the performance then, but making working code first would be good

hidden smelt Sep 1, 2023, 3:38 AM

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so i need something Dictionary<submeshID,List<CombineInstance>>()

tranquil lotus Sep 1, 2023, 3:39 AM

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Yeah if ID is consistent

hidden smelt Sep 1, 2023, 3:39 AM

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yeh it is

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since im copy pasting the prefab each time the submeshes will always be the same index

tranquil lotus Sep 1, 2023, 3:39 AM

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Or sharedMaterial could be key I guess 🤔, whichever is comfortable

hidden smelt Sep 1, 2023, 3:40 AM

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hm trying to tihnk how to correctly combine them before applying the final combine

tranquil lotus Sep 1, 2023, 3:42 AM

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Shouldn’t be too complex

hidden smelt Sep 1, 2023, 3:48 AM

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        public static void Run2(in Mesh prefab, IMeshDeformPath path, out Mesh result)
        {
            result = new Mesh();
            result.name = prefab.name;

            var verts = prefab.vertices;
            var newVerts = new Vector3[verts.Length];
            List<CombineInstance>[] combines = new List<CombineInstance>[prefab.subMeshCount];
            Mesh[] meshes = new Mesh[prefab.subMeshCount];
            CombineInstance[] finalCombines = new CombineInstance[prefab.subMeshCount];

            for (int i = 0; i < path.Length; i++)
            {
                //new mesh for each step along the path
                var m = Object.Instantiate(prefab);

                //deform to conform to the path
                for (var v = 0; v < verts.Length; v++)
                    newVerts[v] = Update(verts[v], i, path);

                //set the vertices
                m.vertices = newVerts;

                //add its submesh data to the list
                for (int s = 0; s < prefab.subMeshCount; s++)
                {
                    if (combines[s] == null)
                        combines[s] = new List<CombineInstance>();

                    combines[s].Add(new CombineInstance() { mesh = m, subMeshIndex = s });
                }
            }

            for (int i = 0; i < combines.Length; i++)
            {
                meshes[i] = new Mesh();
                meshes[i].CombineMeshes(combines[i].ToArray(), true, false, false);
                finalCombines[i] = new CombineInstance() { mesh = meshes[i], subMeshIndex = i };
            }

            result.CombineMeshes(finalCombines, false, false, false);
            result.RecalculateBounds();
            result.RecalculateNormals();
        }
``` seem to get only one submesh output all the rest are culled

tranquil lotus Sep 1, 2023, 3:48 AM

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The submeshIndex for last combine should be 0

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Both mesh is merged down to single submesh

hidden smelt Sep 1, 2023, 3:49 AM

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for result i set it to false so there should be two submeshes no?

tranquil lotus Sep 1, 2023, 3:49 AM

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I mean finalCombines[1] has single submesh

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So it’s CombineInstance should have 0 for submeshIndex

hidden smelt Sep 1, 2023, 3:50 AM

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yeh it shows one

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but it should have a second one

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ill do a step through see if its actually populating correctly

tranquil lotus Sep 1, 2023, 3:51 AM

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I mean this line

finalCombines[i] = { … submeshIndex = i }

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Should set submeshIndex = 0

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Not i

hidden smelt Sep 1, 2023, 3:52 AM

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but then all submeshes have index 0

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when one should be 0 and the other 1

tranquil lotus Sep 1, 2023, 3:52 AM

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No that’s not final index for submesh

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That’s submesh index for the mesh you are giving

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Put it 0 and see

hidden smelt Sep 1, 2023, 3:53 AM

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oh you so smart blushie

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thanks ! i had been over complicating it after all

tranquil lotus Sep 1, 2023, 3:54 AM

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Yay! Glad it worked

hidden smelt Sep 1, 2023, 3:55 AM

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i dont fully follow why it had to 0 but ill take it ! 😄

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i presume because a mesh with 1 submesh but the index starting at i>0 would basically be ignored?

tranquil lotus Sep 1, 2023, 3:56 AM

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Because each meshes you trying to combine now has 1 submesh

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Yeah

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That would be nothing

hidden smelt Sep 1, 2023, 3:56 AM

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tis a pain having to create multiple new meshes just to throw them away again

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unity really could do with cleaner api on that

tranquil lotus Sep 1, 2023, 3:57 AM

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Yeah you might need custom algorithm when you optimize it

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But enjoy for now

#How are you calling CombineMeshes now