Creating a thermal map will typically be done with image editing software that allows you to edit each channel of an RGBA image.
2.6.2.1 Creating a thermal map
Vehicles only require RGB channels for Thermal (that's half cooling factor, alive factor, and movement factor). The alpha channel is only used for people and animals that maintain a static body temperature. The following instructions apply to Photoshop:
Start by opening the colour texture of the vehicle, and changing it to greyscale
Reduce the image size by half, since resolution of the thermal imaging is generally much lower than normal, large textures aren't so important here and it will save some filesize and video ram.
Reduce contrast of the red channel so that it is nearly all 50% grey, and for the blue and green channels make them nearly black but just so you can still see all the detail in the texture.
Use the dodge tool in the green channel to lighten any areas related to engine/exhaust. In my example I've put intense heat on the hood of the truck, the grille, in the front wheel wells, and also on the underside where I just painted in the area of the engine block, and a fake exhaust pipe and muffler. I also added a lesser degree of heat to the quarter panels, fading out away from the engine.
Similarly with the blue channel for movement, use the dodge tool to lighten the treads, parts of the sidewalls, and also the wheel hubs which can heat up from friction and braking. There are one or two deficiencies in the UV mapping of the sample model, the axles are not uv mapped correctly so I can't heat them by movement without editing UVs. Also the cargo cage around the back of the truck is uv mapped from the hood, which means that it will be affected by engine heat unless I fix this (I'll come back to this).
Finally when I am happy with green and blue channels, I edit the levels or curves and make the whole texture darker so that all the dark grey details disappear into black, without losing the brightness of the white engine/wheel areas.
The image can be saved to the vehicle's data directory with *_ti_ca.tga naming. Using the same naming as the colour texture is a good idea, in this case it will be saved as datsun_white_striped_ti_ca.tga.
Image 2-10: Photoshop, showing a completed thermal map and also the component channels.
2.6.2.2 Creating an RVMAT with a TI stage
Thermal imaging is done by shaders in VBS2 so an RVMAT file is needed to setup a TI pixel shader stage, and provide a link to a thermal profile bitmap.
Create a new text document in the vehicle's data directory, name it datsun_white_striped.rvmat and open it in notepad.
Add a stageTI with a texture link to the new TI texture that was just created.
Save it
Now in Oxygen, open the vehicle model and in every visual LOD where this colour texture appears, apply the RVMAT to the material slot. If your vehicle uses three colour textures then you will most likely need three thermal maps to match each of them. This can be a painstaking process, so I created an O2script to speed up the mapping of RVMATs. It is probably good to attempt this manually first to understand the process so you will know what the O2script does (and how much time it can save you).
When your RVMATs are applied to the model, save it. Testing thermal profiles can be done in Buldozer, this is explained below right after the O2script instructions
Alternatively, use the O2script "createAndApplyThermalMaterials.bio2s"
Note: This is an internal developers tool made to speed up the process of applying or patching RVMATs on vehicles, it is a little rough around the edges. For this process you don't need to create the RVMAT manually as detailed above, it will be automatically created when needed. If RVMATs already exist for the model, the stageTI will simply be appended at the end, or if a stageTI already exists in the RVMAT, it will simply be skipped. Save your model first, and play with the script a few times before saving the results, so you get an idea of what it is doing. It will be improved over time and included in the next tools release.
Find the attached zip file containing the scripts (see bottom of page)
Place the .bio2s script file somewhere like P:\tools\oxygen\scripts\
In O2 use Automation > Scripts > Manage Scripts..., then browse to this bio2s you just stored.
Leave all settings default then hit the Add As New button, and the script will now be available in Automation > createAndApplyThermalMaterials
Open the model for which you have just created a thermal bitmap, then run the script. A dialog opens with three lines: the current color texture map, a suggested RVMAT name, and a suggested thermal map name.
Look at the colour map name, and if it is one of the textures for which you created a thermal profile, then choose an RVMAT name to create, and make sure the Thermal Map entry contains a correct path to your new thermal map. It is not autodetecting files here, it simply assumes from the colour map's <filename>_co.tga that the thermal map should be <filename>_ti_ca.tga.
When the RVMAT and TI map entries are correct, then accept. No action will be taken until it reaches the end of the list of found textures. You can exit the script before it gets to the end of the list and no changes will be made at all. The script will cycle through all color maps found in the model and ask for RVMAT and TI pairs for each. When it finds textures such as for headlights or glass, no TI should be assigned to use the skip/ignore button.
On accepting or skipping the last texture in the list, the actual processing will begin, and the script console window details all changes being made.
2.6.2.3 Testing Thermal Profiles in Buldozer
Buldozer now allows direct switching to a thermal imaging mode, it is activated by Right Alt + N. With Buldozer in TI mode, you can now use the following additional controls:
rAlt+F1: Force full alive heat
rAlt+F2: Force full movement heat
rAlt+F3: Force full metabolic heat
rAlt+F4: Don't try this, Alt+F4 is still a Windows shortcut to close the current program!
rAlt+F5: Disable autocontrast
rAlt+F6: Cycle TI blur intensity (blur distance seems constant, this changes the opacity of the blur over the original image)
rAlt+F7 and F8: Cycle through TI colour ramps, there should be seven options at the moment: white/black, black/white, green/black, black/green, orange/black, black/green, and yellow/purple.
rAlt+F9 and F10: Decrease and increase brightness value, measured in degrees Celsius
rAlt+F11 and F12: Decrease and increase contrast value, measured in degrees Celsius from the brightness point.
Image 2-11: Left to right, no heat source, then engine heat source, plus finally movement heat source.
Image 2-12: Once the vehicle has a thermal profile, it can be displayed using a variety of colour ramps to show hot vs cold.
Productivity tools for thermal map creation, contains a Photoshop javascript and an Oxygen O2 script.
