So here's one of my more recent pieces of work, an M84 Flashbang. As I had done a lot of concept work recently I thought it was time I got back to making some game props and continue to practise my texturing and the general pipeline to keep it fresh in my mind. I wanted to make something interesting rather than say a barrel or a crate etc. So with the recent releases of games like COD Advanced Warfare and in particular the Beta for Battlefield Hardline (this is where the SWAT idea came from) I decided to make a first person prop. I went with the Flash bang because its got a really interesting shape with the holes punched out in the body of the grenade. So first things first always get plenty of reference before you start, so I looked at plenty of images to understand how the grenade works and how its all put together as well as the texturing which was important later on. With that sorted I was ready to start modelling.
Low and Highpoly Mesh
Here's both the low and high poly models I made, I didn't actually do any sculpting on this one. First I modelled the High poly version in Maya as it's really easy to reverse engineer it into a low poly model as you can see on the left. As I said at the start I wasn't going to decimate the low poly to far as the idea is this is a first person mesh, although it could be decimated further for the 3rd person model, but the poly count isn't to bad especially with all those holes in the body.
A little Tip
If your new to Maya then here's how to start removing your loops to make a clean low poly. You cant just select a ring and hit delete as you still leave all the verts, in the end you'll be left with a mesh full of 5 sides and Ngons everywhere as well as a high poly count still. So to remove the loop and all the verts on the loop, double click to select the loop, hold control and right click then go to "edge loop utilities" then "to edge loop delete"
When I finished the Lowpoly it was on to Uv unwrapping the model and then moving onto setting up the normal maps.
With the High and Low poly meshes ready its time to make a base normal map.
For the Normal map I used Xnormal, it's a really awesome free program that's great for making maps. If you haven't used Xnormal before I suggest watching a video on the basics of how to use it but its fairly easy to use if you know your way around other 3d programs. For best normal map results its advised to make a cage as you can see above. I made my cage in Maya, and a Cage is basically a duplicate of your Lowpoly mesh that encompasses both your High and Lowpoly mesh but you want it to only just cover it. In some areas you may need to hand edit your cage for the best results. The cage helps to encapsulate and project the detail from the High to the Low, if you want to know more about how it works then this is a great video that really helped explain to me how it works. It can be frustrating when you first learn how to do it, but once it clicks its very satisfying.
https://www.youtube.com/watch?v=kGszEIT4Kww
A good starting point for making your cage as shown above is to select all your verts, then go to the move tool on the left change your movement to Normal mode and then pull the verts out on the N axis. This will scale it out in a uniformed way.
Normal Map
Here's the finished normal maps, to create all the bumps and cracks with in the normal map I used the Nvidia normal map creator plug in for Photoshop. This is an awesome plugin for Photoshop as you can convert your diffuse map into a Normal map. So with the first Normal map I made in Xnormal which is your base, I then converted the diffuse using the plug in and put this on top, set it to Overlay mode and you have your finished normal map with all that nice bump detail from the scratches that you painted in. You can also Filter > Sharpen this if the bump detail isn't strong enough.
Diffuse Map
This is where most of the time is spent, making the diffuse is a long process but rewarding when its complete. I'll briefly explain the process I used to make this but if you'd like to learn more and how to make really cool textures then here's an awesome tutorial series on next gen asset creation and texturing that really helped me out.
https://www.youtube.com/watch?v=oK0b2SUjhtU
So to start I made a lightmap. A light map is where you set some lights up in your Maya or 3s Max scene and then bake the lighting information into a flat image. In Maya I used the Transfer Maps in the rendering tab an then select the Shading map option. This is a great starting point as it makes your texture look less flat, its basically fake lighting information in your model but when its rendered in Marmoset or a games engine it just looks so much better as in real life even in really dark light items still catch some lighting bouncing around, this helps in those scenarios. I also masked off my UV islands and added a base colour for all the pieces in this case its mainly a very dark grey as I was going for a anodized finish. With this base layer it makes it easy to select areas of UV and edit the texture. I also made a brushed metal texture, dirt layer scratches etc, its a matter of building it up slowly. I try to build it up methodically so start with the metal, then overlay the base colour, then extra colour such as the blue paint, the graphics such as Swat etc, then the scratches and last the dirt. Duplicating parts of your texture and changing the blending modes can get you good unexpected results as well as editing the levels and brightness/contrast.
Specular Map
Once I finished the Diffuse your on the home stretch, to make the Spec make it's very simple, I first flatten the Diffuse (Tip: save your diffuse.psd first with all the layers so you can edit them later if necessary) and dropped the saturation right down so your back to black and white. Then I adjusted the brightness and contrast to make a much stronger contrast in the darks and light.
I also made a cold to warm gradient from left to right as well as a multicolour gradient. both these layers were very low in intensity but it makes for some really nice lighting in the Spec as you revolve around the object. The blue to red gradient is very subtle, but the multicolour is slightly more visible, it adds a really nice finish to the texture when it passes through different light.
Gloss Map
Finally the Gloss map is very simple, I just took the Spec map and in the curves adjustment increased it by 20%.
With all that completed this was the final result. I was really happy with how this turned out especially the Spec map when lit in marmoset it rendered really nicely, I didn't want to just make a generic Flash bang as the standard army green is just a bit boring. So I went for a little more of a Sci-fi feel with the typeface although kept the original Flash bang design and I think it works, I think it would fit well in a modern SWAT FPS, COD SWAT edition perhaps instead of all this jet pack nonsense, but that's my opinion :).
If you like my work, CG art or want to learn more about it and how it's done then follow me fore new posts everyday ;)
Jamie
