In the article we’re gonna have a look at how we can set up the displacement inside of or shaders. I’m actually using a different scene because I think it’s gonna be a little bit clearer to see what we’re doing.
Essentially we have got a plane object with 10 subdivisions on each axis. Sitting on a floor with some area light just kind of lights it up.
Now I’ve got a displacement map he just basically a mountain range which I exported, so we can have a look at how to apply this to a shader.
So 1st we open the displacement shader or the rs material which applies one the plane. First of all, we’re gonna need a displacement node, so come to the utilities you can find this on the displacement folder so drag one of those.
- Now you got the options here for scale so that’s the over all height of displacement.
- We’ve got options for the kind of map we are using either height field which is also a standard displacement map we’ve also got a vector displacement map if you’re exporting vector map say from ZBrush another sculpting package.
- We’ve got the Space Type normally just leave it in object mode.
- We’ve also got the ability down below to remap the input range of our map itself.
So we are load in displacement map here, Bring the texture node by drag into the shader graph. I’m gonna override the gamma just set it to be one that is linear because essentially these values are just linear height values.
so we attach the displacement texture to the Rs displacement node as a texture map slot. Now we need to connect the displacement not to the shader(rs material) itself but to our output node.
So we take the output of the rs displacement and connect it with the output node.
Now so far as you can see we haven’t actually got anything going on here. That is because we need to do a couple of things first.
So we come to our plain object and right click, we’re gonna add a redshift object tag to this.
- Click the Redshift tag, then we comes to the geometry tab and override it.
- We also need to come down to a displacement enable it.
Now you see it actually starting to displace our points a little bit. We can also control the sort multiply for scale here on the tag as well. So we can set the displacement height we can also set it inside the shelter itself on the actual displacement tag.
So actually adjust the value per project on the actual tag itself, it means you can have multiple shaders on different objects you can adjust your scale multiply individually.
If we increase the size 5 for example. So far we are not getting too much, we actually need to also make sure that we have a Maximum displacement set to the same amount as the Displacement Scale. You can see we are actually starting to push the points up now.
This maximum displacement essentially abounds for the Max size the polygons can move so we need to kind of set this to be at least the same value as your displacement scale.
So If you have any less is actually in a clip the points. So you do need to make sure these two. You did need to make sure this one is at least the value of your displacement.
Also see: Best Guide on Cinema 4d Deformers
Auto Bump Mapping
Now so far you can see we’re getting a lot of detail here, but most of this is coming from this Enable auto Bump mapping.
Case of what we got here essentially this displacement is just pushing these points based on the map. So Redshift has this cool feature called enable auto bump mapping, if enable that you can see we’re getting a lot of the relief from a map On the geometry as well even though we haven’t actually got the geometry to support it.
This is kind of a unique feature to redshift what it does is if your geometry doesn’t have enough detail in it to actually capture all the details in the map it was split out the extra high-frequency detail and apply as a bump map on top so it is pretty cool because actually gives you the ability to use less geometry and still get a nice result.
So obviously we’re going to want to have more of a subdivision on our geometry to capture the shape of our displacement map better.
So if we come to redshift object tag we have a look at a tessellation. So far displacement just moving the points that we already had but tessellation actually subdivides these further.
If I turn off the Enable Auto Bump Mapping you can see the actual geometry we getting is still fairly large with enabled we actually get the extra level of detail soo high-frequency bump mapping here. So I would always just keep this on anyway.
We’ve got the option for subdivision Rule, normally we just leave it on the Catmull-clock+ loop. Loop is essential to using the loop algorithm for any triangles in your geometry.
We got Smooth subdivision here, it essentially rounding our subdivision corners.
So we’ve also got controls here to adjust our UV smoothing by default it’s set to all ages you can set it to internal edges and we disable it altogether. So you do have the ability to smooth your U. V.’s along with the subdivision of your object in general.
How do we go about adjusting the overall subdivision off our your geometry?
So this tessellation is actually mainly controlled in redshift through this two-parameter here. We’ve got the minimum edge length and we got this maximum subdivision.
So If I just turn off the screens space Adaptive for seconds we can see that what redshift gonna do is if look at the length of the edge of all polygons, each individual polygon here so its gonna say if the polygon is greater than this link maximum edge polygon.
Now if it is it basically subdivide your geometry again and I’ll keep doing this until either the geometry is less than this minimum edge length here or we reached our maximum level of subdivisions.
So essentially if you bring this down. We are reducing the length of the polygon of the lie to be. If we reduce the minimum edge length to 0.3. Now each polygon has to be smaller than a point 0.3 it’s gonna get subdivided. If we go lowest point 0.1. It’s getting subdivided further.
So the higher it goes the more subdivisions you can have you can get slower as you get more. Of course, you also have the option just to set your minimum edge length so it’s kind of a way of balancing this two up.
Now screen space adaptive disabled this value he’s actually in world spice units so it’s calculating this based on the overall size of the polygon edge inside of the scene.
So the thing is this is actually getting subdivided quite uniformly at the moment so we’ve got the same level of subdivision here at the front and we have at the back. So you don’t always need to have sorry much subdivision in the black, because nobody can see it so much.
It’s smaller in the overall size of the render, so you don’t need to have quite as much detail on top of that we also have this innate or type bump mapping so we are getting the high-frequency detail added on top as well.
So I hope this article helped a lot and you understand the concept the Displacement in redshift so that you can implement it and makes your artwork beautiful!