The VRscans material contains parameters and attributes that are user-changeable according to the needs of the scene. This allows for customization and tweaks if desired in the scene to adjust to the lighting and creative needs of the project.
This section needs screen grabs and further explanations of what the parameters are, and how they work and if anything is different between the platforms.
VRscannedMtl Parameters
Adjust UV tiling – the .mtsc file stores information about the physical size of the scanned sample surface. Texture tiling is adjusted by clicking on a point over the scene object to resize the texture to fit in the correct scale.By clicking on a point over the CG object, the texture tiling is modified so that the texture is with the correct size for the clicked point
Plain materials strategy – simplifies the shading of the material and may help to reducing tiling artifacts [HOW does this work?]
Filter color – used to tint the color of the material. Specifically, this parameter is used as a color multiplier to adjust the HSV of the material's scanned color.
Information – this text field found in the UI [where?] displays useful information stored in the .mtsc file. Information fields are created during the scanning process by _____(is it requested? Is it manually input like tags?)
This information can include the following:
- The size of the physical sample used to scan the material
- etc
- etc
Subdivision – controls how many reflection rays will be traced for the material. Note that the material does not have a "diffuse" or "reflection" component - everything is considered glossy reflection. (Why will we use this, is it for quality/speed?)
Trace depth – controls the number of reflection bounces. A value of -1 means that the reflections bounces are controlled by the global V-Ray trace depth in the Global switches rollout of the renderer settings.
Cut-off – a threshold that is used to speed up reflections. If the contribution of reflections falls below this threshold, the reflections are not traced. This is similar to the cut-off threshold of the VRayMtl material. (Want to see example images of how Cut-off controls the reflection)
Glossy as GI – this parameter is useful for debugging purposes and is equivalent to the same setting in the VRayMtl material. (Why would we use this, in what cases do we need it and how will it help debug the scene?)
Coarse indirect – simplifies the calculations of the material when it is viewed through GI rays. In that case the Average BRDF method is used to shade the material (see above). (Need explanation of when and why you'd need to use this.)
Uniform reflection distribution – when enabled, the material reflections are computed by sampling the hemisphere uniformly. When disabled, importance sampling is used to put more rays in directions where the material contribution is larger. Which method will perform better depends on the scene lighting and the particular material that is used.(Need explanation of when and why you'd need to use this as well as a comparison of renders and render times to further illustrate when to use one over the other.)
IOR – determines the IOR of the coat layer and from that controls the strength of the reflections. A value of 1.0 does not produce any reflections and disables the coat layer. Higher values produce stronger clear coat reflections. The .mtsc files typically contain the correct value for this parameter and it is set automatically when the file is loaded. (Want to see example images of how IOR can be changed if at all)
Bump multiplier – the coat layer has a built-in bump map stored into the material sample file. This parameter allows to control the strength of that bump. (Want to see example images of different bump strengths)