Modelling Error (Normals??)

I’m making a few custom models for a TTT map. I’m using blender and everything is going fine aside from one issue.
Multiple faces on one of my models seem to be visible from only one side. When I make the normals inside the faces that were visible switch and show the outside.
Is it the way I UV mapped?

The flower from a top down angle.

The flower from the side.


You’re right, that’s probably the normals, go to blender in edit mode, select all faced with A and press CTRL+N, that will recalculate the normals, which hopefully will be enough to fix this, if for some reason it’s still fucked up then you’ll need to set them manually, press N when in edit mode and go to the mesh display section (I assume it’s in cycles because I always use it), there you can select to show normals, either for vertices, edges and faces, select faces and see which normal is not facing outside, mind you if the geometry is 2d one side will always be invisible, when you find the odd one out just select the face and flip normal.

That is the way I did it. Thanks for telling me I can do it manually. But in regards of “mind you if the geometry is 2d one side will always be invisible” How are certain objects like bushes or other foliage, from either HL2 or CSS, with 2D or single planes able to maintain that “doubled sided visibility.”

That’s beyond me, I am sure there’s an answer, I was going to see how by looking at the cactus which has 2d spikes going on both sides but have yet to do it, I assume it’s a command in the VMT.

Not that big of an error, but normals are a type of bumpmap. You guys are talking about faces.

Well that’s awkward, we’re referring to Normals in blender, as in the way blender determines the outside and inside of a mesh, also the way it determines which side a texture is projected, I am sure he already knew that a Normal Map is another way of saying Bumb Map.

normal maps are a supplement to the geometrys normals. normals are just a physics oriented concept of “direction” that is utilised in pixel shading.

in regards to the problem you may need to either find a way to bypass some kind of “backface culling” or you may need to find some way to have it shade as double sided. i recall blender has an option for double sided normals but ive never used it so i cant vouch for how useful it will be. you may be able to bypass the issue by simply doubling the geometry with opposing normals.

It looks like this is indeed an issue with the mesh itself being a collection of one-sided planes. And, as mentioned previously, due to the normals, they can only be seen from one side.

You have two solutions to this:

The better solution is to duplicate all of your single-sided planes, and then simply flip their normals. That way, you have 2 planes on top of each other, one facing up, the other facing down. No matter which side you view it from, only one side will be visible.

The faster solution is to apply $nocull 1 to your material VMT. This will cause both sides of the one-sided plane to render, but lighting information will only be received from the “correct” side. Depending on your use application, this might be fine, or it might cause severe lighting oddities. For a prop this small, I think you’d be fine, but it’s still worth noting why this idea isn’t a catch-all solution.

Enabling Double Sided Normals on blender Works well inside blender , but i dont know if it works well on source , you just have to try it out