Warehouse scene: Composite maps vs Unwrapping - using Total Textures

Introduction

This particular scene was used as the basis for two chapters in 3DCreative magazine, as part of a tutorial dedicated to post production techniques. The series focused on how Photoshop can be used to enhance 3D renders by way of compositing different passes as well as looking at the numerous image adjustments that are frequently used in the process.

During this tutorial we will focus on the advantages of using Composite maps to create a multi-layered level of detail and show how texture co-ordinates can be manipulated within the material editor to avoid unwrapping geometry.

Composite maps work in a similar way to the blending modes available in the Layers palette in Photoshop and enable various textures to be combined on a single surface. As we will see, they also incorporate the use of masks which can offer further control over how each map appears in relation to one another.

In this case we will be looking at how these are used in conjunction with 3ds Max, but these techniques and materials should be applicable in other 3D packages too.

The majority of the textures used in this tutorial came from the 3DTotal Textures collection.

<h6>{Total Textures Collection V1 - V19}</h6>

{Total Textures Collection V1 - V19}

Fig.01 shows the scene in question: a simple corridor with the camera placed at one end and the corresponding view (inset). It is set in an industrial context and one that is in a state of decay with crumbling walls, debris, damaged pipe work and loose cables. The textures need to reflect this state of decay and so I used quite a few from 3DTotal's most suitable texture collections, notably Total Textures V02:R2 - Aged & Stressed , and Total Textures V05:R2 - Dirt & Graffiti

Fig. 01

Fig. 01

Fig 04

Fig 04

Total Textures V2:R2 Aged & Stressed

Fig 05

Fig 05

Total Textures V5:R2 Dirt & Graffiti


The main part of the scene is composed of the actual corridor itself, which is a single mesh as seen in Fig.02. This has been assigned a Multi Sub-Object material which means that an ID number is allocated to each face and corresponds to a material ID. In this case the corridor mesh has been divided into five sets, as shown in the material editor on the left. These five ID numbers make up the entire mesh, e.g. the floor polygons are assigned the number 2, the left wall 3 etc.

Fig. 02

Fig. 02

Therefore when a texture is applied to Sub-Material 4 it will appear on the back wall only.
Most of these five Sub-Materials are assigned a Composite map, which means that when the material tab is clicked for ID 2 (Floor (Standard)), for example, it opens another sub level where the standard Diffuse or Color map is labeled a Composite (Fig.03).

Fig. 03

Fig. 03

Notice at the top of the dialogue box under the toolbar that we can see the number [2] on the left next to the name Floor. Beside this on the right is the Standard tab which corresponds to the Sub-Material in Fig.02.

When the Composite tab (Map #126 (Composite)) is clicked it opens up a dialogue box similar to Fig.04.

Fig. 04

Fig. 04

Here you can alter the Blending mode and Opacity of the texture as well as apply a mask. You can see in upper right that the floor is made up of eight layers in total, five of which are visible here.

All the layers have been turned off, barring Layer 1, as indicated by the small glasses icon left of the texture tab in Fig.04.

This single base Layer is visible in the scene in Fig.05, which at the moment looks very uninteresting.

Fig. 05

Fig. 05

If we switch on Layer 2, which is set To Multiply at 60% Opacity, you can see this now adds a new layer of detail and variation to the initial texture (Fig.06).

Fig. 06

Fig. 06

By clicking on the actual texture tab you can gain access to the coordinates and map parameters (Fig.07).

Fig. 07

Fig. 07

Here you can reposition the map on the geometry by way of Offset as well as control the Tiling, which in this case has been moved along the U axis by 0.07 and tiled by 6.0 in both axes. This is the Layer 2 texture which is set to Multiply.

The next Layer contributes a section of dirt along the right edge of the floor and uses a mask to do so. In Fig.08, texture 1 represents the dirt and texture 2 the mask that is used to control its visibility.

Fig. 08

Fig. 08

In Fig.09 you can see just the dirt map on the left and how the Offset and Tiling coordinates have been modified to position the map along the right hand edge. It is tiled only along the U axis, which corresponds to the length of the corridor.

Fig. 09

Fig. 09

The Tile checkbox is not ticked in the V axis and therefore only partially covers the width. The dirt texture (Brown08) is tiled by 6.0 in both axes and so covers the entire floor area, but the mask reduces its visibility to just the right edge within the white area.

Layer 4 in the composite map represents the line of dirt along the opposite wall, the mask of which is visible in Fig.10. As in the previous layer, the mask has been offset and tiled to only run along the wall edge whereas the dirt texture covers the entire floor. The difference here is that the dirt texture is set to Multiply as opposed to Normal.

Fig. 10

Fig. 10

When activated, the result can be seen in Fig.11.

Fig. 11

Fig. 11

When this layer is now made visible, along with the previous three, we can clearly see how the composite map works compared to Fig.05 where only the base layer is evident (Fig.12).

Fig. 12

Fig. 12

When all eight layers are active the result is a muti-textured surface that has avoided any unwrapping or custom texture creation in Photoshop (Fig.13).

Fig. 13

Fig. 13

The advantage of using this technique is that it only requires a simple planar map and dispenses with the need for unwrapping as the coordinates for each of the textures can be manipulated individually in order to localise detail, using a mask to control what is visible.

The trade off is that the scene can be heavily laden with textures as a single surface can use several as part of a Composite map, so depending on the project limitations this should be a consideration.

Fig.14 shows the far wall using a more conventional texture that composes of a single JPEG which has been manually put together in Photoshop using a number of source images. It uses a Standard material with a single color map assigned to the Diffuse slot (inset).

Fig. 14

Fig. 14

You can see in Fig.15 how at least six different textures have been combined to create this texture.

Fig. 15

Fig. 15

The same technique has been used for the door, which incorporates three textures from Total Textures V17 - Urban Extras Textures.

<h6>Total Textures V7:R2 Urban Textures</h6>

Total Textures V7:R2 Urban Textures

Door_09 has been set to Darker Color within Photoshop in order to reveal just the rusted areas and the graffiti from door_13 has been extracted and then set to Overlay on a separate layer (Fig.16).

In the case of the right hand wall, both of the above techniques have been used, i.e. an unwrapped template used as part of a composite layer.

Fig. 16

Fig. 16

In Fig.17, the mask from Layer 2 (tile02medium_13 V05:R2 - Dirt & Graffiti is visible in the scene which is creating a stain using the opposite texture (1).

Fig. 17

Fig. 17

<h6>Total Textures V5:R2 Dirt & Graffiti</h6>

Total Textures V5:R2 Dirt & Graffiti

The base layer however is a custom texture made in the same way as in Fig.15 & Fig.16 and has been created over a wireframe guide that represents the unwrapped wall (Fig.18).

Fig. 18

Fig. 18

The red arrow indicates the two sections of wall to the right and the lower section corresponds with the two panels at the opposite end (green arrow). The black "L" shape has been left incomplete as this section of wall falls outside of the camera view. The two horizontal lines towards the top of the wall represent the grime and shadow from the two larger pipes.

The final scene can be seen in Fig.19, which is built up from both composite maps and custom textures created in Photoshop.

Fig. 19

Fig. 19

To see more by Richard Tilbury, check out Digital Painting Techniques: Volume 4
Digital Painting Techniques: Volume 5
Digital Painting Techniques: Volume 7
Beginner's Guide to Digital Painting in Photoshop Elements
Beginner's Guide to Digital Painting in Photoshop
Photoshop for 3D Artists
and Prime - The Definitive Digital Art Collection

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