Hello all,
I found out how to render both side of my model in 3DS Max, but how am I supposed to have it render all the sides in Unity?
How it renders the sides in 3DS Max:
And here is how it renders in Unity:
Is there anyway to make the inside of my engine visible without having to duplicate all of the inside mesh, making it a little smaller (to hide it), flipping the normals of the duplicate, and then attaching it to the existing mesh?
There are two ways to do this without duplicating faces.
This issue occurs because Unity uses “backface culling” to speed up rendering times. (More info on backface culling in Unity here: Unity - Manual: ShaderLab: commands). Because this is a shader issue, both solutions require editing shaders.
The first solution is to create a shader which has culling turned off. This is very simple and just requires the line: Cull Off to be placed in the shader. This will work, but has issues with lighting. The back faces (the ones that are currently invisible) will have the same lighting and texture as the front faces. With this method, this cannot be avoided.
However, there is a second, more complex solution. You create a second material, and apply that to the object as well. While the first material has backface culling, your second will use a custom shader with frontface culling. This means it will draw exactly the opposite faces as the first one (i.e. all the faces that were culled by the normal shader). With this method, you can place a different texture on the inside face. Getting the lighting to work is a little more fiddly, and requires you to alter the vertex normals in the shader. I hope to release a collection of basic inverted shaders at some point using this method, to allow people to easily solve this problem.
EDIT: Shaders to do this can now be found on the asset store. Applying one normal material and one “inverted” material can allow both faces to be rendered with correct lighting, as well as different textures and normal/specular maps.
If @Hoeloe’s assumption is right that you’re trying to render backfaces, then ignore me. However if it’s just that the faces in section of your model that represent the inside of the engine that are invisible, your issue might simply be that your normals are flipped in that area.
To check this in Blender (Sorry I don’t know 3DS Max), look at the object with the “backface culling” option selected (found in the dropdown on the top right next to viewport settings). If you can see through faces, select the objects you can see through in the scene tree on the right. Then select all vertices of the part of the object that looks wrong in Edit mode and press ALT+N to bring up the normals menu, then select “flip”.
