Displacement ModifiersChapter 2 - Realistic Rocks

In this tutorial we will utilize Displacement maps to create some of the more chaotic organic surfaces in nature, like rocks.

To start, open 3DS Max and create a box from the Geometry under the create tab.

I have created this box, and given it a Length, Width, and Height of 75.0 with

5 Segments in each as well.

This will give us a fairly low amount of polygons to start, as we will be utilizing another method of increasing our poly counts in order to get some more exact edges.

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Next, we are going to make sure our box is selected and go to the modifier tab. From the drop down list, we are going to find the Spherify modifier and add it to our box.

This modifier does exactly what its name would suggest. It makes other objects look as much like a sphere as possible.

Once you have added it, you'll see that the settings consist of a percentage of 0 to 100.

Minor Spherification to Full Spherification. It's default is 100 and we will leave it at this.

You might ask why the heck didn't we just create a sphere?

The answer is, you absolutely could have just made a sphere. However, when you create a sphere from the geometry section, look at the top and bottom where the poles would be if it were the planet earth. Notice that they are made up of triangles. Triangles don't smooth as well as Quads, you tend to get a pinch effect out of the top and bottom of a sphere instead of smooth edges.

Using spherify lets us avoid these triangle polys, and in turn will allow for a much smoother model.

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Now remember I said we were going to use a different method for giving us some extra poly counts that will allow for a smoother, more precise edge, this is it. Go to the modify tab, and add a MeshSmooth modifier. What comes next can get us some very nice edges for something like a rock, but in normal circumstances should be avoided unless you are sure it is the right way to go, it has crashed many a decent computer in its day.

Add 5 Iterations in the Subdivision Amount rollout settings.

Next, Add a Displace Modifier to the stack. Make the Strength: 40, and make sure that it is set to Spherical in the Map settings.

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Then click on the None button under Map: in the Image settings.

Then select Cellular from the resulting list and click OK.

You should see quite the change to your box in the perspective view now.

Which means we need to police this unruly rock.

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Open your Material Editor (M) and Click and Drag the Cellular Map we just added, to an empty slot in your Material Editor.

Then when the pop up box shows up, be sure to select Instance so that any changes we make in the Material Editor, will transfer over to the Displace Map.

Now you can adjust the settings for your Cellular map to make it look much more like a stone.

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Make the Cell Color black.

The Division Color #1 a light gray and #2 a dark gray.

In the Characteristics area:Make the Size 35.0Spread 1.5

And change the Mid: threshold to .8.

These settings will vary based on what you want the Larger portion of your rocks texture to look like. Experiment here to see what different kind of rocks and boulder shapes you can createYour finished map should look something like this in your Material slot.

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Take a look at that unruly stone now:

Now that is something we can work with! This displace modifier is for the large details of a stone or boulder.

Check out some various reference images of stones and boulders to get an idea as to why we started this way.

Once you are satisfied, we need to add another displace modifier to our stone for some of the medium details.

Go back to your modify tab with your stone selected and add another displace modifier to the stack.

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This time give it a strength of 2.0

Click the None button under Map and select Noise from the list this time.

Make sure Spherical is marked.

Then click and drag the Noise map we just selected to another empty slot in our material editor and select Instanced.

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Noise Type: FractalNoise Threshold: High: 0.9 Levels: 10.0

Size: 30.0 Low: 0.3

Adjust these settings based on how you want the medium level details of your stone to look. Once you are finished experimenting, scroll down to the Output rollout and select: Enable Color Map

This activates a curve we can adjust to further give us some controls over the Noise we are using.

<---- Enable Color Map

<---- Use the Add point button (3rd from the right) to add several new points along the line. I added 6.

<----- Then adjust those points to create a jagged curve, much like the surface of a rock should be!

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The noise in your material slot should start looking harder edged when you adjust these points along the Output line.

Now go see the results on your model:

Getting closer.

Now we need to adjust the minor details of our stone some more, and mix these up a little.

Go back to your Modify tab with your stone selected and add a Noise modifier to the stack.

Set the Scale to 270.0Mark Fractal

Iterations: 8.0

All three strengths should be about 40.0

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Notice those nice crisp edges we had from our original Cellular displacement have now kind of ... crumpled up a bit giving it a more natural looking broken edge.

Then add another Noise Modifier for good measure and reduce your settings to another level. This gives us a couple different variations on the smallest details.

Set the Scale: to 100Mark Fractal

Iterations 10.0

All three strengths set to 4.0

Look at your stone now:

Not too bad, all that's left is to squish this sucker down a bit so it isn't quite so ... square.11

You could grab your scale tool and squash it down ... but instead lets use another modifier called an FFD.

With stone selected go to your Modify tab again, and add an FFD 2x2x2 to your stack.An FFD Modifier sets up a series of Control Points which we can use as envelopes to manipulate our rock.

Instead of squishing it down and out, we can move each corner down in order to add an extra bit of chaos to our natural stone.Click the black x next to the FFD modifier in your stack in order to see the selections available. Then select Control points.

Then select the corners of the orange bounding box that now show up as little squares and move them around until you are satisfied, pull them towards the ground to squish the rock down and then vary them a bit to make it a more natural squish.

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That's it! you have successfully modeled a fairly realistic looking stone out of a box using the Displace Modifier and several others you should be familiar with already.

All you have to do now is add a texture to it, and stick it in your scenes!

**Challenge!Try creating other kinds of rocks, boulders, stones, and asteroids with this technique. Experiment with the settings to see what you are capable of!**

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