Two Ways to Generate Z Depth in 3ds Max

What You'll Be Creating

1. Z Depth With Mental Ray

Step 1

I have made a very simple scene for the demonstration. This scene contains several spheres. I have also applied some materials and set the rendering engine to Mental Ray. I have set a camera also.

Creating a simple scene

Step 2

I have added and positioned several Omni lights in the scene. I have chosen Ray Traced Shadows as shadow type.

Ray traced shadow

Step 3

Press the F10 key to open the Render Setup window. In the Renderer tab, set the Minimum value to 4 and the Maximum value to 16. Select Mitchell for the Filter Type.

Renderer

Step 4

Now render the scene. It looks nice, but the depth is still missing. I can enhance the overall look by adding a Z Depth pass while compositing.

Rendering the frame

Step 5

In general words, a Z Depth pass is a grayscale image, similar to the alpha channel for the graphical representation of depth.  In a Z Depth pass, every pixel in a scene is assigned a 0-255 grayscale value based upon its distance from the camera.
The objects closest to the camera are white and the objects furthest from the camera are black. It gives an extra sense of depth and realism after compositing. Look at the image below for a before and after comparison.

Z Depth

Step 6

See how I generate a Z Depth pass using Mental Ray. Press the F10 key to open the Render Setup window. In the Render Element tab, click on Add button and choose Z Depth from the list. Click on OK.

Adding Z Depth pass

Step 7

Press F9 to render the frame. You can see a grayscale Z Depth pass. The objects closest to the camera are white and the objects furthest from the camera are black.This is not the correct Z Depth pass as I don’t know the exact distance between the camera and the objects in the scene.

Z Depth pass rendered frame

Step 8

To know the exact distance between the camera and the objects, Z Min and Z Max values will help. Z Min defines the distance between the camera and the closest object. And Z Max defines the distance between the camera and the furthest object.

Z Depth element parameters

Step 9

To measure the distance, I need a tape. So, go to Helpers > Tape and draw a tape from the camera to the closest sphere.

Using tape

Step 10

Pick the tape’s head and you will get its value. This is the Z Min value.

Z Min value

Step 11

Put the value in Z Min box.

Z Min value

Step 12

Pick the target of the tape tool and put it beside the furthest sphere from the camera. Pick the tape’s head and you will get the Z Max value.

Z Max value

Step 13

Put this value in Z Max box.

Z Max value

Step 14

Press F9 to render the frame. Now you will get a perfect Z Depth pass along with the Diffuse pass.

Final Z Depth pass

2. Z Depth through MAXScript

Step 1

Michele Marcelli has written a very useful script for creating Z Depth. You can go to www.scriptspot.com to obtain the script. The best thing about it is that the script is free to use.

Free script

Step 2

Download and install the script. Normally you have to put the script into the Scripts folder of the 3ds Max root directory.

Install the script

Step 3

Back in 3ds Max, go to MAXScript > Run Script. This opens the browser, select the script and click on Open. This opens the script’s window.

Run Max Script

Step 4

Click on Pick and Select Camera button. Press H to open the Pick Object window and here select the camera.

Pick camera

Step 5

Click on Preview Z-Depth (Selected Camera) button. Within a couple of seconds, you will see a preview of Z Depth pass in the preview window. The output result looks good, but a bit grainy. So I need to tweak some values.

Preview Z Depth

Step 6

You can play with the Z Min and Z Max values to get the desired Z Depth pass. Each and every time you need to check the pass clicking on the preview button.

Z Min and Z Max

Step 7

Once you are satisfied with the preview, click on Render VFB button. This will show you the final result.  

Final rendered frame of Z Depth pass

3. Compositing

Step 1

Open both the Diffuse and Z Depth pass renders in Photoshop.

Open Photoshop

Step 2

With the Z Depth layer selected, press Crtl-A button to select the entire image and then press Ctrl-C to copy the image.

Copy the Z Depth image

Step 3

Now deselect the Z Depth layer and select the Diffuse layer. Then go to Channels tab.

Open Channels tab

Step 4

In the right side corner, click on the drop down arrow menu and select New Channel from the list.

New Channel

Step 5

It opens the New Channel window. Give it a name, such as Alpha 1.

Rename the channel

Step 6

With the Alpha 1 channel selected, press Ctrl-V to paste the copied Z Depth image.

Paste the channel

Step 7

Go to Layer panel once again. Now, with the Diffuse layer selected, go to Filter > Blur > Lens Blur.

Apply Lens Blur filter

Step 8

It opens the Lens Blur window. The image look totally blurred and out of focus right now.

Lens Blur window

Step 9

Select Alpha 1 as the Source channel and set the Blur Focal Distance to 255. Now you will see an extra realm of depth in the scene as some part of the image gets blurred partially and rest of the part remains in focus. This happens due to the Z Depth pass.  You can easily control the amount of the focus and area of focus with the parameters of the lens blur effect.

Setting the parameters

Conclusion

I hope you have enjoyed these ways to create Z Depth pass in 3ds Max. The script written by Michele Marcelli is the fastest way to get the Z Depth pass. The script is totally free to use, however if you find it useful, you can donate an amount to the creator of the script as a return gesture. This is only a matter of choice.

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Creating Realistic Clouds in Autodesk 3ds Max Using Particle Flow and AfterBurn

What You'll Be Creating

AfterBurn is a great volumetric plugin for Autodesk 3ds Max. In this tutorial, I'll show you how to use AfterBurn, along with Particle Flow, to create a realistic puffy cloud scene. I'll finish by doing some compositing in Adobe After Effects to make the result look even better. 

1. Creating the Wire Structure

Step 1

First of all go to Create > Particles > Particle Flow Source.

Creating PF Source

Step 2

Then draw a PF Source icon in the perspective viewport.

Creating PF Source Icon in the Viewport

Step 3

Click on the Modify panel and then click on the Particle View tab. Alternatively, you can press the 6 key on the keyboard.

Ways to Access the Particle Flow 

This opens the Particle View window:

Opening the Particle View Window

Step 4

Select the Speed, Rotation and Shape operators and then delete them, as these operators are not required for creating static clouds. If, however, you want some motion in cloud puffs then you can play with these parameters later.

Deleting Several Operators

Step 5

Select the Birth operator and set the values of Emit Stop as 0 and Amount as 10.

Setting the Birth Parameter

Step 6

Select the PF Source icon in the viewport and change the Viewport % value to 100.

100% Particles in the Viewport

Step 7

Set Icon Type as Box and set the Length, Width and Height values as 50, 80 and 10 respectively. The values may differ in your case.

Changing PF Source Icon's Parameters

2. Applying AfterBurn Effects

Step 1

Go to Rendering > Environment, or press the 8 key on the keyboard.

Opening Environment Window

Step 2

This opens the Environment and Effects window. Inside the Atmosphere panel, click on the Add tab. This opens the Add Atmospheric Effect sub-window. Select AfterBurn and click OK.

Applying AfterBurn Effect

Step 3

You will see AfterBurn and FusionWorks Renderer are added to the list.

Applying FusionWorks Renderer

Step 4

Apply a standard Target Spot light in the scene. I have done it this way to illuminate the AfterBurn particles. I can always change its settings at a later stage.

Applying a Target Spot Light

Step 5

Turn on the Shadow option and choose AB Shadow Map. Increase the Multiplier value a bit and choose a light blue color for the light’s color.

Changing the Parameters of the Light

Step 6

Press 8 on the keyboard to open the Environment and Effects window again. Select the AfterBurn effect which opens the AfterBurn Manager below.

Opening AfterBurn Manager

Step 7

First click on the Pick Particles/Daemons icon, and then select the PF Source icon in the viewport. This adds the PF Source to the list. Click on the Show in Viewport icon to see the actual shape of the AfterBurn particles in the viewport.

Selecting the PF Source Icon in the List

Step 8

Click on the Pick Lights icon and press the H key to open the Pick Object window. Select the spot light and then click on the Pick button. You will see the spot light gets added to the scene.

Selecting the Light Source in the List

Step 9

Render the scene now. At this stage it still doesn’t look very realistic. I need to tweak some parameters and their values and then it will look much better.

Rendering the Scene

Step 10

First of all, go to the Particle Shape parameter and change the Sphere Radius to 25 and Squash to 1.5. Set the Variation percentage to 50.

Changing the Radius Value of AfterBurn Particles

Step 11

Go to the Rendering parameter, change the Falloff to 1.5, and turn on the Self Shadows option. This will enable the cloud to generate and receive its own shadow.

Changing the Falloff Value

Step 12

Render the scene to see how it looks. Now we can see the cloud formation clearly. But I've still got to change a few more things to make it look like a realistic cloud.

Render the Scene

Step 13

Go to the Shading parameter and change the Ambient Color to light blue. After rendering the scene you will clearly see the difference in the ambient shadow part.

Changing the Ambient Color

Step 14

Go to the Noise Animation parameter and change the Noise Size to 25. Set the Type as Smoke and don’t forget to turn on the Cubic option.

Changing the Noise Size

Step 15

Render the scene again. Now the cloud looks much better.

Render the Scene

Step 16

You can increase the Density to 5 to check the result.

Increasing the Density

Step 17

Press 6 to open the Particle View once again and this time decrease the Amount to 5. A smaller amount of particles will make only one or two big puffs of cloud.

Decreasing the Number of Birth Particles

Step 18

Change the Shadow Falloff value to 1.5 to make the shadow a bit smoother. Also decrease the Opacity amount to 0.7 or 0.8 to reduce the darkness of the shadow.

Changing the Falloff and Opacity Values

Step 19

Now let’s render the scene and see how it looks. You can check from any angle. It looks pretty good.

Render the Scene

Step 20

Try tweaking some more parameters and their values to get different results. Decrease the Noise value to 15 and then render the scene to check how it looks.

Changing the Noise Size

Step 21

To add some more variation decrease the Hi Threshold value to 0.7 and the Low Threshold value to 0.2. It adds fractal and turbulent edges to the cloud.

Changing the Threshold Values

Step 22

This time increase the Noise value to 20 and select the Cubic option. The Cubic option adds much smoother and feathered edges to the cloud.

Decreasing the Noise Size

Step 23

Once you’re satisfied with the settings, go to the Smoke parameter and increase the Levels value to 15. Now render the scene and you will see more detailed cloud puffs.

Increasing the Levels Values

Step 24

Go to Rendering > Render Setup. This opens the Render Setup window. Here go to the Renderer tab and select Catmull-Rom as the Filter.

Changing the Rendering Filter to Catmull-Rom

Step 25

Now render the scene once again. The Catmull-Rom filter makes the rendered frame sharper.

Rendering the Scene

Step 26

Increase the Length and Width values of the PF Source box. This will scatter the cloud puffs across a broader area.

Scattering the PF Cloud

Step 27

Go to Rendering > Environment and set the Background color as black.

Black Background

Step 28

Render the scene. The cloud looks quite nice. It's time to do some compositing in Adobe After Effects and add some effects to make the final result look much better.

Rendering the Final Frame

3. Compositing in Adobe After Effects

Step 1

Open After Effects, import the cloud footage, and place it on the timeline.

Opening After Effects

Step 2

Press Control-Y to create a new Solid Layer. The solid layer color should be white. Put this white solid layer behind the cloud layer.

Creating a Solid Layer

Step 3

Take the Ellipse masking tool and, while pressing Shift-Alt, mask a circular area in the white solid layer. This will act as the Sun. Add some feathering as well.

Masking the Solid Layer

Feathering the Mask

Step 4

With the white solid layer selected, go to Effects > Sapphire Lighting > S_Rays. Use the same settings as shown in the image. You can play with the values to get different results.

Adding Rays

Step 5

Make another solid layer and make its color royal blue, just like the sky. Put this layer beneath all the layers.

Creating a Royal Blue Background

Step 6

With the cloud layer selected, press Control-D to make a duplicate layer of it. Select the upper duplicated layer and apply the Brightness & Contrast effect. Use the values shown in the image.

Adjusting the Brightness and Contrast

Step 7

Pick the Pen tool and make a mask around the cloud layer as shown here.

Making a Mask Around the Cloud

Step 8

With the upper white solid layer selected, go to Effects > Sapphire Lighting > S_LensFlare. The settings shown in the image will give a nice lens flare effect.

Step 9

Finally, add a Tint effect to the upper cloud layer to make it a bit unsaturated.

Adding Tint Effect

This is the cloud I made following the same procedure. You can play with the settings, parameters and their values to get different results. I hope you enjoyed the tutorial. Do share your results and views.

Final Scene

A Composited Scene

A Different Look with Live Element!

Conclusion

In this tutorial I’ve shown you how to create a puffy cloud scene in 3ds Max using AfterBurn and Particle Flow. AfterBurn is a great volumetric plugin for 3ds Max. You must give it a try. I hope you have enjoyed the tutorial.

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