How to process sub_model material of aiPrimitiveType_LINE in .ac model

[unsanedingding]

Question: I use .ac format model.

1. 1.How to process sub_model material of aiPrimitiveType_LINE ? In .ac model ,have som axis (only have two vector3d vertices ),in this case, need material?

[irajsb]

Can you provide an example file so I can see for myself ?

[irajsb]

how do you plan to draw lines in unreal ? real time engine only draw triangles not lines . and a line will not have a face so it will not need a material to be drawn on the face.

[irajsb]

You can apply scale like this

SceneObject->SceneScale = 100.0f; is a readable variable not to be set by user

[irajsb]

Hi you can see the Blueprint in releases section of the github page.

[irajsb]

I've pushed an update to repo that fixes that issue Here is the release The model should have normals from modeling software but these can be also generated with assimp .

[irajsb]

when the mesh is imported try to preview its collision and see if its built correctly .(top left of 3D viewport change from lit to player collision )

[irajsb]

Num Collision primitives 0. collision is not generated for your mesh .

[unsanedingding]

So, how to config param of assimp for generate collision data, or ... I need generate collision by manual at runtime?

[irajsb]

assimp has nothing to do with collision at this use case . unreal is responsible for creating the collisions of the meshes . I've tried some other meshes and it seems like it generates a simple collision for them .
check the logs for any errors regarding creation of static mesh.

[unsanedingding]

Some error....

(n)LogAssimp: Error: This algorithm works on triangle meshes only

(n)LogStaticMesh: Warning: StaticMesh_0 has some nearly zero bi-normals which can create some issues. (Tolerance of 1E-4)

(n)LogStaticMesh: Warning: StaticMesh_0 has degenerate tangent bases which will result in incorrect shading. MikkTSpace relies on tangent bases and may result in mesh corruption, consider disabling this option.

So, I need set bRemoveDegenerates and bRecomputeNormals and bRecomputeTangents property on build setting and giveup use StaticMesh build, Change to use GetMeshDataForProceduralMesh and apply use these property? Right?

thank you.

[irajsb]

No I don't think those errors are collision related https://blueprintue.com/blueprint/inhg2zu3/ You can also try this method instead of creating static meshes

[unsanedingding]

Thank you I test GetMeshDataForProceduralMesh version:

Thanks a lot.

[irajsb]

can you provide the example model again? I think it was removed

[unsanedingding]

Thank you very much, thank you.

[irajsb]

I can see a perfect collision here

[irajsb]

I'm using the release version nothing special.

[unsanedingding]

Thank you. 1.release version? Only can not work at editor mode ? So, it's means support LineTrace? 2.How to show this effect at editor mode?Or how to get this result (effect), by some setting on Editor? 3.Can hited by LineTrace in PIE? Maybe... LineTrace cannot use to generate meshed at runtime?

[irajsb]

this is how to preview collisions as I mentioned before. line trace is working unless you are using wrong channels for tracing (tiny red square is where hit is happening when I use line trace single by channel)

[unsanedingding]

Thank you . Can you share your the showing project as before? Thank you.

[irajsb]

I don't understand the question

[unsanedingding]

I use line trace on fbx version of same mode, result is correct，when i change to assimp version of these model by same code, line trace hitd result alwasy false (invaild). So, i'm very confuse : ) BTW, I also have not config any Tag for all model. In assimp Imp version, I try to multi function of linetrace serices, all small button(switchs) allways can not be hited.

[irajsb]

Maybe you are using wrong collision channels when tracing ?
Also try to enable debug view for you traces .

[irajsb]

https://github.com/irajsb/UE4_Assimp/releases/tag/MajorBugFix here is the version that I'm using code is in level blueprint

[unsanedingding]

Oh, I think i had find some different...use your original test project of above the link (Thanks again)