Overhaul Textures Workflows

Some workflows and information on texture creation for Overhaul.

4x Upscaling Existing Texture DDS

This is a multi-step process, but reasonably simple, to obtain a upscaled PNG file.

1. Crunch the DDS file back to PNG (this "flips" it)
2. Run Cupscale with the models below in a chain (first one, then the other) for the texture (or set of textures):
   1. 1x_artifacts_bc1_free_alsa.pth
   2. 4x_BSRGAN.pth
3. Save resulting PNG as the base diffuse (xxx_d.png) file.

Then you use this as the basis for the others, and if you need to scale back to 2048x2048 or smaller use Crunch to do it at the DDS stage.

4x Upscaling Existing Texture TGA or other

Same as above but you can avoid the Crunch step; just run Cupscale on the TGA file with 4xBSRGAN.pth model being run. It'll self-convert to PNG automatically.

Upscaling Textures with Transparency

This can be a big pain in the arse. Things like leaves or whatnot. Some notes to follow and check out 4x Texture Upscaling pages for some attempts at formalising it.

Converting to DDS

The intermediary file, usually PNG, could be TGA or another uncompressed format, can be converted using NWN Crunch: https://neverwintervault.org/project/nwnee/other/tool/nwn-crunch-enhanced-edition

There are some reasonable default cmd scripts but some edits are needed for doing:

• Non-alpha using 4096x4096 textures with DTX1 - this compresses a lot better when you don't need that alpha layer
• Converting dimensions downwards, such as making portraits smaller using one base large image

See the SVN for these scripts.

Final DDS should be as close to the original sizes as possible, keeping under 15MB, see Overhaul Models and Textures at the bottom for notes on this but basically with alpha it is usually 2048x2048 maximum and without alpha it is 4096x4096 - although only needed on very large creatures like Dragons or Giants.

Existing Diffuse adding PBRs

The mainstay of content for the Overhaul to begin with will be using upscaled 4x textures with PBR additions.

Starting Tutorial: Using ShaderMap 4 (SM4) to Make Simple PBR Textures

If a creature is quite "dry" and "normal" we can just do a normal map. This adds some shadowing on the model where bumps are in the texture.

Using ShaderMap 4 we just simply add the image we want to create normals from, which will generate a basic normal map - to have it to NWN standards change the green channel to be Y+

(shamelessly from the tutorial above) Select the normal map then click the axis icon in the bottom left panel.

Next, click the box at the top of the green axis.

Click the checkbox to accept the changes.

Specular and Roughness

These maps provide a shine to the object.

However it's not as simple as "just export stuff from ShaderMap 4" or any other tool, since:

• You might want the entire model to be "shiny" (or wet) and the specular map isn't quite correct for that
  • This might just mean the spec/roughness maps are purely one colour, which simplifies things
• You might want different levels of shiny - ie wet, metallic, reflective and so on
• Environment maps may be needed to add some additional gusto
• The changes to the original diffuse by having a roughness and specular map may mess up the colouring quite a bit

Specular maps:

• This should be "how much it is shiny" - or "Specularity signifies just how much of the incoming light is reflected"
• The values are 0-255 based on the RGB values - so a as the value goes toward 1 (white), this will also result in the material behaving as metallic. IE: White == maximum reflective, Black == not reflective.

Roughness maps:

• Compliment specular maps, in so far as you can be shiny but not metallic which is where roughness comes in
• should by themselves be enough for "shiny/wet" but doesn't seem to be the case on non-flat planes, or difficult diffuses so...have to use a specular too
• It's again a Black-White 0-255 image. You'll want to have greys generally, White == maximum roughness and Black == no roughness.

Some experimentation is required here and for different types.

Using shader variables

This might be easier than having a ton of DDS files which essentially are one uniform colour. Saves a lot of disk space and file mess too.

Example MTR c_ettercap.mtr - the top two lines force normal maps and specular/diffuse compared to leaving them blank, taken from the PBR demo module (bit more on default shaders used here: https://github.com/mtijanic/nwnee-shader-tutorials/blob/master/tut/material-fragment-shaders.md ). The values though will just be uniform for the model, as if we produced an entire specular/roughness map which was all uniform white or black or grey.

customshadervs vslit_nm
customshaderfs fslit_nm
renderhint NormalTangents
// Textures 
texture0 c_ettercap_d
texture1 c_ettercap_n
parameter float Specularity 0.02
parameter float Roughness 0.1

Example code to change the values for testing - debug console - select the ettercap and apply.

    float fSpecularity = 0.02;
    float fRoughness = 0.05;
    SetMaterialShaderUniformVec4(OBJECT_SELF, "c_ettercap", "Specularity", fSpecularity);
    SetMaterialShaderUniformVec4(OBJECT_SELF, "c_ettercap", "Roughness", fRoughness);

Example values see here: Enhanced Lighting Engine and PBR

• Specular: General rule of thumb of having about 0.02 for liquids, 0.04 for solids, except metals, which instead should have values close to 1.0.
• Roughness: Highly polished surfaces will have about 0.05-0.1 and very rough surfaces like natural rocks, bricks and similar will be about 0.6-0.7.
• Water:
  • Spec 0.02
  • Roughness: 0.1
• Metal:
  • Spec: 1.0
  • Roughness: 0.0
• Bricks:
  
  • Spec: 0.04
  • Roughness: 0.6

However having something that is "wet but solid" instead of water needs some testing. It sometimes also benefits from the diffuse file (main colours) being altered to remove shadows or lighten them up.

Some examples:

There's a Metallicness value set in the shader too. We'll look at that another time...the shader defines it in inc_material.shd and seems to be auto generated anyway:

uniform lowp float Specularity;
uniform lowp float Roughness;
uniform lowp float Metallicness;

Default definition: fMetallicness = clamp(fMetallicnessModifier * fSpecularity - fMetallicnessMod, 0.0, 1.0);

Code to test:

    float fSpecularity = 0.02;
    float fRoughness = 0.05;
    float fMetallicness = 0.05;
    SetMaterialShaderUniformVec4(OBJECT_SELF, "c_ettercap", "Specularity", fSpecularity);
    SetMaterialShaderUniformVec4(OBJECT_SELF, "c_ettercap", "Roughness", fRoughness); 
    SetMaterialShaderUniformVec4(OBJECT_SELF, "c_ettercap", "Metallicness", fMetallicness);  

Environment Maps

These provide some colourisation information to the model where things are reflected. The default games version without PBR's is a bit lackluster.

The "default" option uses the texture file "chrome1"

This applies - as it looks like - a bit of a silvery-shine.

Needs further testing on how we replace this default or, well, how it works overall. Some aspects of implementation:

• TXI (urg) can define it with EnvMapTexture
• MTR can supposedly use Texture15 for it, this needs further testing
• You can specify a texture filename in the appearance.2da entry (not a terrible idea, but only works for creatures not placeables or tiles)