How do Iray shaders work?

HonzoHonzo Posts: 193

I see Iray shader packs in the store, for floors, walls, fabric. Can these be applied to any surface? Are they practical to use?

Comments

  • GordigGordig Posts: 10,049

    Yes. You can apply any shader to any surface you want, although how good it will look depends on a number of factors, including tiling and the UV setup of the item. 

  • HonzoHonzo Posts: 193

    Interesting- seems like a way to multiply the utility of lots of different items at pretty low cost. Any hazzards I should particularly look out for? As, for instance, applying them to an outfit?

     

  • GordigGordig Posts: 10,049
    edited February 2022

    Outfits can be tricky, because it can depend on the material zones. Take dForce Willow as an example (odd example, I know, but stick with me). See that it has flannel fabric, white probably cotton material and a leather corset. If each of those is a separate material zone, then you could apply a different shader to, for example, the flannel, and only the flannel will change. If, however, the creator used a single surface for all of those different physical materials, then the shader would overwrite all of those different materials. Despite having picked that as my example, and actually using it somewhat often, I don't actually know how the material zones are set up on that particular piece, but it's an example of what might happen. Similarly, if a terrain prop has rocks, grass and other items on it, those might be separate surfaces, or they might all by part of the same surface. You could potentially apply a ground shader to the ground and find that your rocks all look like dirt now. 

    Post edited by Gordig on
  • HonzoHonzo Posts: 193

    I think I see- each mesh is divided into zones for materials/shaders, yes? So that can mess things up if they aren't where you want them. Is there a way to 'repaint' the zones on a mesh? 

     

     What, by the way, is the difference between a material and a shader in DAZ?

     

  • GordigGordig Posts: 10,049

    Honzo said:

    I think I see- each mesh is divided into zones for materials/shaders, yes?
     

    Ideally, they are, but that's not always the case, and some items are just a single material zone. Even some items that have multiple material zones don't have as many as users would like them to have.

    Is there a way to 'repaint' the zones on a mesh? 

    You can use the Geometry Editor tool to assign polygons to surfaces, and create/rename delete surfaces as well. Using the example above, if the corset on that outfit weren't its own surface, you could select all the polygons of the corset and create a new surface called "corset" (or whatever you wanted) that you could then apply shaders to.

     What, by the way, is the difference between a material and a shader in DAZ?

    The terminology gets a little tricky, because what most DS users call a "shader" is actually a shader PRESET. If you're working on Iray, the overwhelming majority of time you're going to be using the Iray Uber Shader base, which determines which parameters you have to work with. Daz has a couple other distinct shaders for Iray, and some PAs make their own as well, but most of what you see in the store is just presets for the Uber base. Materials are the same way, in that a material preset includes texture maps, but also shader settings. The most crucial difference between materials and shader( preset)s is that materials are made for specific items, whereas shaders are more generalized. If you apply a material preset to, again, the Willow dress, it will look for the specific material zones and apply the texture maps and shader settings to those material zones. Shader presets are less targeted, meaning that they can take more work to apply to whatever you want them on, but it also means that you can use them on anything. If you tried to use a material preset for the Willow dress on anything but the Willow dress, almost certainly nothing would happen, because nothing else is likely to have the same material zones as that dress. 

  • HonzoHonzo Posts: 193

    Great explanation! Thanks!

     

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