Final render

To finish off I used the in game rendering tools in UDK to produce a beauty render of the diorama with correct lighting and composition.

Asset placement

Finally after all of the materials had been created and all of the meshes had collision applied to them I began to place the assets in a good and presentable arrangement. Finally I ensured that all of the asset's light maps were correct by building the lighting on the level and fixing any issues.

The complete package

Above you can see the complete UDK package including all meshes, materials and textures. All of the meshes have complete collision and have the materials applied, including decals on the main digger.

Creating materials using shaders

The first thing to do once in UDK is to create the shaders that the materials will use when applying the various texture components to the mesh, above is an example of a simple material with complete diffuse, normal and specular connections.

Lightmapping

The final step in preparing the assets for use in UDK was effective light mapping, in order to achieve this I duplicated the existing UV sets for each of my assets and began to unsew and resew sections following a set of rules. Firstly that every shell needed to be approximately two grid spaces apart and secondly that any sewn shell which contained an edge of 90 degrees or more had to be unsewn and made a unique shell. This process was more time consuming than actually difficult.

Specular Maps

The final stage of the texturing process for all of the assets was to create specular maps, to do this I took the layered PSD files for each of the diffuse maps I had created and chose certain layers to alter in terms of brightness. The reason for this was to ensure that once I flattened the image and desaturated it and altered the levels of the image that these sections would still remain fairly bright. These sections included the windows as well as shiny metal sections.

Diorama textures

I made continued use of the photo reference for the diorama textures, using dirt textures to add depth and custom brush to add variation and detail in much a similar way as the main digger asset.

Tiling textures

In order to maintain a higher resolution on my tarmac texture that I would use for the floor of the diorama I decided that rather than have a single texture that would stretch across the entire mesh I would tile the texture across three planes instead. To do this I created a single 512 texture for the ground and used the offset tool in photoshop to make sure the texture successfully tiled with minimal seams, I then UVed the ground to have three overlapping uv shells which took up the entire 0-1 grid space, I then moved the edge of one of the shells as I had decided to texture a white line down the edge of the texture to create more variation.

Diorama Modelling

I began to model my diorama promptly and used photo reference as an example of the kinds of objects one might find on a construction site, to that end I decided that all I needed to model would be a cone, which I would duplicate once successfully UVed as well as a barrier and two variations of sign.

I also decided that I should make the diorama more interesting by including some variation on the ground. I used the deformer tool in maya on a 10x10 poly grid to create an effective hole which looked like it had been freshly dug, this was an attempt to let my diorama tell some kind of story, rather than simply appear as a series of static objects.

Decals

In order to maintain a higher resolution on the logos and decals on the asset I decided to use a decal sheet. In order to make this work I used the reference images of my digger to retrieve the decals that I wished to apply, after successfully cropping them out of the image I created a blank alpha channel and filled the decal areas white against a black background. I then saved out the document as a .tga in order to save that alpha channel.

Next I went back into Maya and created a series of flat planes which I then UVed and resized appropriately to reflect the size and scale of the decal sheet, I then applied the decals with the intact alpha channel to a blank Lambert, this achieved the transparency effect and let the decal be applied.

Height to normals

In order to get more definition to my model without increasing the polycount I used the texture as a basis for the normal map I will apply. I used the door frames as well as the body decoration in conjunction with the height2normals plug-in in Photoshop to generate a normal map.

Texture build up

In order to further build up my texture I found one of the dirt texture reference photos that I took and began to play around with it in photoshop. I first needed to darken it so that it looked convincing, to do this I duplicated the layer and changed the blending mode of the layer above to multiply. This darkened the image and also made the colours appear more saturated. After I had the texture I wanted I needed to apply it to the actual asset texture, to do this I created a layer mask and began to 'erase' sections of the image. I found a custom brush online that created a good natural spattered effect, making the dirt appear as though it had been caked on during operation.

Finally I used this brush at a series of varying opacities to create a gradual gradient and still retain adequate texture detail.

Texture reference usage

After finishing the base colour on the texture I began to star using texture reference to build up the material. I used a galvanised metal texture taken from a warehouse shelf with a few image adjustments in the form of levels and colour balance in order to make it appear slightly aged and discoloured.

Texture base colour

When starting to create a texture for the main digger asset I used the AO bake from Maya as a base layer and edited it slightly using the smudge tool in order to maintain a consistant gradient, to fix a few issues and seams in the bake itself. After which I began to underlay base colours and alter those base colours to create a basic texture ready for future buildup.

Ambient Occlusion and Normal map baking

In order to stay within the poly limit and still maintain a high enough level of detail on the final asset I decided to create a high poly version of the tracks and bake the detail to a low poly mesh in the form of a normal map, above you can see the completed high poly mesh next to a UV mapped low poly mesh exported directly from the main model.

After correctly positioning the two meshes and exporting them as .obj files I loaded them both into a third party application called Xnormals and baked the normal map as shown below.

Finally in order to start texturing I used Maya to bake an ambient occlusion map onto the main model and then used that detail as a layer in a diffuse texture.

UV Layout

Here is the UV layout for the model, ready for texturing. I recently noticed that the Gantt chart posted before did not have UV mapping as a separate stage, I rolled it into the time factor for the modelling as I made sure during the modelling process to UV some of the components in order to duplicate them and save UV space with overlapping UVs as evidenced above with the darker blue UV shells which are of course multiple shells overlapped.

Finished Model

Here is the model in its finished state. After an optomisation pass I was able to pick up enough spare polys in order to model the lights and mirrors on the main cabin. I have chosen not to model the roof rack that is present in the reference picutres because after some research I have found that it is an extra and not part of the standard vehicle. The proof can be seen below.

Block out

This is the initial block out for my model in Maya, on the right you can see the standard unreal man to ensure the model is correctly scaled. From this stage I can see that the limb is a little too thin and requires a little alteration and the tracks are a little too thick.

Gantt Chart

Above is a proposed Gantt chart outlining my plan for various stages of this project as well as the time needed to completed each stage. I have given extra time to certain stages such as Baking, this is a little conservative and simply my way of planning for things going wrong, which they have a tendancy to do during the baking stage.

Collecting texture reference

In order to create believable textures I went on a trip with three friends namely Tsanko Tsanev, Bryan Devenish and Tim Nightingale around the city collecting photographs we believed would make interesting texture reference. These ranged from tarmac textures to dirt, to metal and stone. Our destinations ranged from DIY stores such as Homebase and B&Q to actual construction sites which we were able to gain permission to enter. Below are a few examples of photos taken.