[Blender] Weird overlapping + Bonus questions

Hey guys. So,I started making my first serious model using nothing but a physical representation. So far so good, but I'm running into a couple graphical errors and I also have a few questions.

First and foremost, my model is a lighter. I plan on integrating functionality in unity later, but this is obviously more important. The model for the most part is complete. Right now, I'm just trying to UV map it and give it textures.

Here are a few pictures of the model:






If you notice the gas press button (I really dont know what its called lol. The red piece you push down) has some graphical errors.
Here it is with some grid textures on it to show you:



So how can I get rid of this??

Also one more question, and sorry for all the pictures haha.. Again, kinda nooby to all this.

So far I have been doing the following workflow to make and apply textures. Is there something Im doing wrong or something I could do differently?

- Make 3D model
- Export smart UV layout
- Export UV layout to photoshop
- Set background as either checkers or color map
- Select certain parts of model in blender to see which part on the UV map is for what
- Draw/paint in selected part
- Export edited UV to unity as a texture
- Apply texture to model as a gameobject


I know Im probably doing some things wrong. Especially with applying the textures? It's worked, but sometimes its meh. Also with the editing UV layout. It's hard to see what I'm doing while painting on top of the outlines. Is there some trick I can do to paint below the outline but not have the outlines show up as part of the texture?

Painting over it is fine, but again it makes it hard when you paint over certain lines that are close to others.

Also.. Faces and triangles.. How do I reduce them? How do I get rid of unnecessary parts faces and vertices etc? Do I just have to go and get rid of as many as I can or is there some option in Blender?

Thanks a ton guys. The response to this will really answer most of my questions. Getting closer and closer to developing something cool

 

Things I see from the start: darker bluish-gray polygons means that their normal (surface direction) is inverted. If you enable Backface Culling in view properties, you'll see what I mean. Unity renders polygons only from one side, so you'd want all the normals to point outside (Mesh - Normals - Flip Normals for the inverted faces). The flickering artifact on the button part is called Z-fighting (You have 2 duplicated polygons that occupy exactly same space, and the program cannot decide which one to render first). Delete the duplicated geometry. Also about your workflow. Using automatic unwrap, especially on a simple object, is not a best idea. I'd recommend you to unwrap manually, selecting one area at a time, so you'll know from the start what each area represents on UV map. Here is nice short tutorial on how to use mark seams + unwrap: