Join Aaron F. Ross for an in-depth discussion in this video RGB curves adjustment with an output map, part of 3ds Max: Advanced Materials.
- [Instructor] Previously we saw how a color correction node can be used to non-destructively alter the colors of any map. Let's look at an alternate way to do that using an output map. This gives us the ability to adjust color function curves, very similar to the curves adjustment in Photoshop. I've switched my renderer back to ART, we can see that in the render setup dialogue. I'm in active shade mode with ART as the renderer, with a target quality of 28 decibles.
Let's open up the material editor. I've created three physical materials and assigned each one to one of the parts of the sculpture. We've got helmet, hair, and body. And they're all preassigned to the objects in the scene. For the helmet and the hair physical materials, I've connected a bitmap to their diffuse color, or base color map. And those of course are the ambient occlusion passes that we just rendered out in the previous movie. Let's enable or disable the use so we can see them more clearly in the viewport.
Select the hair physical material and up on the slate material editor toolbar we can disable show shaded material in viewport. And here it is without any ambient occlusion in the diffuse channel. Turn that back on again, toggle that so you can see it, likewise with the helmet object we can select that physical material node and toggle the state of show shaded material in viewport. Let's create that shaded network for the body, physical material, we'll need a bitmap.
In the material map browser under maps general, here's the bitmap, drag that over. And choose athena_body_AO.png from your sceneassets images. If you don't have it, I've got one inside the examples folder there, you can steal it from there if you need to. Click open and that path is now assigned to the bitmap node. We can double-click on the thumbnail, make it bigger. And we could connect it directly to the base color or anything we want, but if we're going to work smart rather than work hard, we want to send this through a separate output node.
If I double-click on the node and look in the parameter editor, you'll see down in output we have the ability to control the color, we have the ability to control a function curve as well, directly built into the bitmap. But I recommend that you create an output map instead, and pipe your bitmap through that. And that will give you the freedom to perhaps maybe have multiple output maps feeding into different parameters here. So we'll find output under maps general once again.
Drag an output map over and connect the bitmap to the output map and then the output map to the base color of the physical material. And we can see that change. Double-click on the output map and open up the output section and we can start playing around with these parameters. Output amount is gained, turn that up to, let's say five. And we see it become much brighter here, kinda blasted out, maybe two.
I would leave the output amount actually at a value of one but play around with RGB offset and RGB level. This is a bit more predictable. RGB offset is the black point. We could bring that down a big, maybe negative 0.5. And now we've pushed all of the RGB values down. We can compensate for that by increasing the RGB level. Let's try a value of positive 1.5. And now we've effectively increased the contrast on that.
If we want to compare this color adjustment or transform with the original image, there's no disable switch for the output settings, but we can work around that by rewiring the nodes here. If I drag from the bitmap output to the base color on the material, now we see no transform applied. And if we drag from the output node back onto that base color, we see it become darker.
All right, so we can just keep doing that. And that lets us do a sort of AB comparison. All right, so that's how you use the output map in its most basic function. Let's set these RGB offset and level values back to their default. RGB offset of zero, RGB level of one. And now enable the color map. And we have two modes, mono and RGB. Let's play with the mono version first.
And this is a standard function graph. We have the input values from black to white here at the bottom, and the output values from black to white here running vertically. If I bring this point down for example, now I'm dimming that material down by a factor of almost 0.5. I can set that value back up to one, just type it in. Let's create some curve points. Up here on this little toolbar we can add a point, but that's gonna be a corner point by default.
We can hold that button and choose bezier point. And click a couple times on that curve. And now I've got two bezier points to play with. Go into move mode, and we can move the points around and we can move their handles around as well. And we get instant feedback here in the viewport. And this method actually does have a mute switch here. Enable color map, we could disable that. Color map off, color map on.
Very cool, and finally we can also adjust the RGB values. Go into RGB mode and now we got separate curves for red, green, and blue. Let's disable the blue and green curves by clicking on these icons and then move the points on the red curve and observe the result in the view. Maybe go back to enable the green curve. Just play around with it, we can get some pretty strange results pretty quickly here.
And that's just adjusting the points with linear interpolation. We haven't even begin to play around with bezier curves. We can switch back to mono mode, we didn't lose what we had there. And fine tune this in order to maximize the effect of that ambient occlusion, or crevice shadows. Great, that's how we can use the color map or function curves in an output map to nondestructively alter the colors of any incoming map.
- Streamlining material editor workflow
- Managing XREFs and materials
- Laying out a scene for material testing
- Using the Physical Material
- Controlling highlights with Roughness
- Directing reflections and refractions
- Simulating translucency and scattering
- Building a shading network
- Combining and color correcting maps
- Baking maps such as ambient occlusion
- Procedural mapping with Substance
- Using relief maps: bump, normal, and displacement