Category

Rendering

Maya & Arnold – 5 Sequence Rendering

By Maya, Rendering

From the IPR window you can directly save single frames. In the Render View Window go to > Save Image … > Options

iprsaveimage

In the Options popup you need to adapt the Save Mode according to your intended file format. Choose “Save RAW Image” when you want to output .exr or other formats with 32 bit color mode for further processing or compositing with applications like Nuke or After Effects. In most cases you will save a regular 8 bit color jpeg, tiff or png and for these formats you choose “Save Color-Managed Image”, hit Apply and Close” – this is important, otherwise the output will be too dark.

iprsaveimageoptions

When you select > Save Image … (without Options) you can select your desired File type and save it to the images folder.

iprsaveimageas

For rendering animations first of all make sure you have selected the proper frame rate at > Windows > Settings / Preferences > Preferences > Settings. If you don’t have other requirements you can leave the default 24 fps, it works on most devices.

settingsfps

Go to the Render Settings with the little icon from the shelf. At the Common tab switch to any of the options with the # variable to enable sequence rendering. With File name prefix you can specify a custom output name. Choose your desired Image format and leave the default Gamma at 2.2 for regular 8-Bit jpeg, tiff or png file formats, that’s the equivalent to the option “Save Color-Managed Image” described earlier for single frames. Adjust Frame Range and Image Size according to your requirements.

rendersettingssequence

Switch to the Rendering Menu Set at the top left of the UI.

rendershelfswitch

In the now appearing Render Menu select > Render Sequence (new since Maya 2017). The Render View opens and renders frame by frame to “images” in your project folder.

rendersequence

If you want to stop rendering just close the Render View window.

Maya & Arnold – 4 Camera / Depth of Field Blur

By Maya, Rendering

For animation and specific camera setup we need an extra camera for each shot. If you have not yet created a custom camera in the perspective viewport select > View > Create Camera From View (Ctrl+Shift+C). Rename the new camera and make it the active camera in the Viewport > Panels > Perspective > Your Camera Name. To activate the depth of field blur in the Attribute Editor go to the CameraShape node, activate “Enable DOF” in the Arnold section (not in the Depth of Field section, that’s for the Maya standard renderer) and increase the Aperture Size.

enabledof

With the default focus distance of 1 cm everything becomes blurred in the IPR.

defaultdof

To find out the right focus distance we need to measure it. Let’s temporarily hide unnecessary objects by hitting the “H” key. Switch to the default working camera in the Viewport > Panels > Perspective > persp. Activate “Snap to points” from the toolshelf and > Create > Measure Tools > Distance Tools.

distancetool

Click on the camera in the viewport and on the part of the object in your scene you want to have in focus.

distancemeasure

Apply the measured distance to the “Focus Distance” attribute in the Arnold section of our camera …

focusdistance

… and this part becomes sharper.

dofhighalllights

The DOF blur effect is still intense – great for making adjustments. If you don’t want to measure again when the focus distance has changed, first parent the camera locator by MMB dragging it onto the Camera in the Outliner.

camlocator

Rename the second locator to “Focus”. When you now move the camera or the “Focus” locator, the length value on the distance dimension tool should change. To connect the resulting length of the distanceDimension1 with the Arnold Focus Distance attribute in Camera1 just copy paste the following line into the “MEL” script field at the bottom left:

connectAttr -f distanceDimension1.distance Camera1Shape.aiFocusDistance;

Hit “Enter”. Important: To make the script work, your camera needs to be named exactly “Camera1” and the distance tool “distanceDimension1” in the Outliner. If you want to make it work with different names you need to adapt the strings in the script accordingly.

connectattr

If the script was successfully applied you can see in the Attribute Editor the Focus Distance of Camera1 became yellow and is now linked to the Distance Tool.

connectattrdone

For final rendering decrease the Aperture Size, I used here 2.

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Maya & Arnold – 3 Three-Point Lighting

By Rendering, Shaders & Texturing

In the last chapter we have set up an environment light – which is great for outdoor scenes or quickly illuminating an object. Three-Point Lighting consists of the Key Light, Fill Light, and Back Light. It refers to situations in reality where several light sources illuminate objects – typically by night, indoors or in situations with bouncing lights. By directing position, intensity, color, shadow behavior of your lightsources you can actually “paint” with light by emphasizing aspects of your model to influence the perception in the spectator. Watch Light & Shadow, an Emmy winning film from director Steve Weiss (20 min) if you want to learn more about the subject. The basic concept of Three-Point Lighting in relation to 3D applications is briefly explained in this Tutorial.

In physical based render engines like Arnold the scene measures refer to real world values. I scaled the displaced terrain from the last chapter to a size of 40000 units (=400 m) which allows me to place a building of  about 7 x 7 and 12 meters on top of the hill. The object I want to see illuminated is called Breather Surface and the building a modified  Menn´s Surface, both are parametric objects created with the free (and still working) Cinema 4D plugins from Jürgen Meier. Create your own building, make sure you cut out enough area for windows.

buildingwireframe

The typical approach to Three-Point Lighting is to start with a Key Light. In our case we already have the environment light which we can use as the Back Light. With the IPR window open adjust Elevation and Azimuth in the aiPhysicalSky to bring the sun close to the horizon. With the main object selected RMB > Assign New Material > aiStandard Material, increase specularity – because every object in our physical world has some (more or less) specularity. You can find out more about specularity and energy conservation in this introduction to physical based rendering. Move around your camera to find a nice framing with the sun highlighting the edge of the objects from slightly above or the side. The default camera in Maya comes with a focal length of 35 mm which is fine in most cases. I widened the angle to 28 mm for capturing more from the room and to make the image more dynamic. Don’t worry about the noise, we will fix that later in the Render Settings.

backlightstart

With the small Icons “Resolution Gate” and “Gate Mask” above the viewport you can overlay the aspect ratio of your final rendering. Once you are happy with the framing in the viewport go to > View > Create Camera from View.

createcamera

Lock your new camera by clicking the small lock icon above the viewport. To move around in your scene and to adjust lights switch back to the default working camera at > Panels > Perspective > persp.

switchcamera

Let’s bring in the Key Light, the dominant light source. In the Outliner select the aiSkyDomeLight and hit “H” to hide it for now. Add > Arnold > Lights > Maya Spot Light. Rotate it above and beside to the camera’s viewing axis. For better visibility you can scale the camera and light symbols in the viewport, it does not affect their beavior. Add some color to the Light and increase the intensity to about 100000. The shadow should be softened slightly at > Radius in the Arnold tab of the light.

keylightsolo

To soften and extend the illumination provided by the key light and to make more of the subject visible, add a > Arnold > Lights > Area Light to serve as our Fill Light. I rotated it away from the object, that the light bounces back from the wall to soften it. Increase the intensity to compensate the energy loss, in my case about are fine. Adding subtle color makes the light composition look more interesting.

filllightsolo

When working with the IPR make sure you leave the settings for exposure and gamma at their default values 0 and 1 as well as View Transform at sRGB gamma. These sliders can be temporarily toggled for diagnosis but must always be switched back by clicking on the icon. The illumination of the scene will be controlled with the intensity of the light sources as well as the brightness and specularity of the materials. Exposure settings can later be adjusted with the camera settings.

iprexposure

The setup from above.

lightsetup

Key Light, Fill Light and Back Light together.

threepointlights

Finally I slightly increased the intensity for all lights proportionally and added specularity inside the building. To reduce the noise I changed > Render Settings > Arnold Renderer > Sampling > Camera (AA) to 8. In the report at the bottom of the IPR window you can see how that increased the render time. For fluent working it is recommended to stay with the default sampling rates, you can even reduce the Camera (AA) Sampling to 1. You only need to increase Camera (AA) Sampling for the final output and quality previews.

threepointlightsimproved

Continue with Maya & Arnold Part 4 – Camera / Depth of Field Blur

Maya & Arnold – 2 Skydome Lighting and Background

By Rendering, Shaders & Texturing

Every render engine has its own set of lights and materials therefore it is important to pick lights for rendering with Arnold always from the Arnold menu. Add > Arnold > Lights > Skydome Light.

aiskydomelight

At the Color attribute of the aiSkyDomeLightShape click on the Texture checkerboard icon and in the Create Render Node popup choose the > Arnold > Texture > Environment > aiPhysicalSky. Alternatively you can select the > Maya > 2D Texture > File node and load an external HDR (High Dynamic Range) image. With their higher bit depth (32bit) HDR images are able to capture the lighting information from real world environments which is helpful to illuminate photorealistic scenes. You can downlad free HDR samples from the sibl archive. When you load 32bit HDR images in Maya (.hdr or .exr) make sure to change the Color Space to Raw. Jpeg and everything else should remain at sRGB. Find out more about the new Maya 2017 color management in the Arnold User Guide.

colorspaceraw

I’m interested in a more artificial look and will continue with the aiPhysicalSky.

aiphysicalsky

Once we have a light in the scene it would render without background:

aiskydomelightonly

To add a background go to the Render Settings with the little icon from the shelf. Switch to > Render Using Arnold Renderer. At the tab > Arnold Renderer > Environment click on the Background checkerboard icon and select the aiPhysicalSky.

rendersettings

The aiPhysicalSky node is only available here if you have it created in the previous step with the Skydome Light. If  you have decided to use a HDR image for lighting you can use the same HDR file as background image. Since the background image linked at the Render Settings does not contribute to lighting, you can use any file here (also regular 8 bit jpeg images). The free HDR samples from the sibl archive come mostly with high resolution jpeg images, they should be preferred here.

backgroundcreateskyshader

At the Color attribute of the aiSky node click on the Texture checkerboard icon, in the Create Render Node popup choose the > Maya > 2D Textures > File node and load an external image.

backgroundcreateskyshaderfile

To make the support geometry of the aiSkyDomeLight or aiSky invisible in the viewport you can switch off the LOD Visibility at the Attribute Editor.

aiskydomelightvisibility

Now with the groundplane selected RMB > Assign New Material.

assignnewmaterial

In the popup window select > Arnold > Shader > Surface > aiStandard.

aistandard

In the Attribute Editor change the diffuse color. Click on the IPR (Interactive Render Preview) button. You might notice a black gap between the terrain and the horizon.iprterrain

The Physical Sky model renders everything black below a latidude of 0 degrees. To fix it create another Poly Plane with no subdivision, scale it to a value of 10000000 (=100 km) place it slightly below the terrain to avoid intersections and with RMB > Assign Existing Material (the same terrain material). If you have changed geometry in your scene you need to klick on the IPR refresh icon to update it. Other changes in the scene like navigation or shader modifications are automatically updated.

iprrefresh

In the aiPhysicalSky node you can influence the lighting and color mood by changing Elevation and Azimuth of the sun. More information about the Physical Sky model with example pictures can be found in the Arnold Manual.

aiskysettings

Continue with Maya & Arnold Part 3 –Three-Point Lighting

Maya & Arnold – 1 Setup

By Maya, Rendering, Shaders & Texturing

Arnold will be automatically installed with Maya 2017, by default version MtoA 1.3.0 (Maya to Arnold), but it’s still possible to manually install newer versions of MtoA. The most recent versions can be downloaded here. To activate it in Maya go to > Windows > Settings/Preferences > Plugin Manager and tick both mtoa.mll boxes, refresh, close.

loadplugin

Let’s create a project folder which conveniently bundles textures etc. associated with the Maya scene in one place. Go to > File > Project Window. Click “New”, type in a name in “Current Project” and change the Location. As soon as you hit “Accept” Maya automatically creates a set of folders there.

projectwindow

Now go to > File > Save Scene As … and save the file to the “scenes” directory. A prefix with the date or a consecutive number makes it easier to navigate between iterations of your work later.

saveas

The advantage of the Project folder is, that files associated with the Maya scene are stored in one place. To share projects with different computers you just copy the complete project folder containing texture maps etc. to the new place. If you want to switch the project folder in Maya simply choose > File > Set Project, navigate to the project folder you want to work with and hit “Set”.

Let’s start with a ground and > Create > Polygon Primitives > Plane or use the Polygon Shelf.

polyplane

Arnold calculates the light decay in real world measures therefore it’s recommended to work with somehow realistic measures in your scene. The default size of the Plane is 1×1, Maya’s default units are centimeters, so we need to increase its size. In the next step we will add a terrain structure to the plane and to make the details visible we need to add more subdivisions to the plane. Be careful here, if you crank up the subdivision too high Maya will slow down or freeze.

planesubdiv

One easy technique to create a terrain is to use the sculpt tool. An alternative texture based method will be explained below. Tostart sculpting switch to the Sculpting tab and select the Lift Tool.

sculpting

Adjust the brush size with B + drag or middle mouse button (MMB)-drag left/right. The brush strength can be changed with M + drag or MMB-drag up/down and pull out some hills. In case your groundplane is cut off in the viewport select the camera in > Windows > Outliner and increase the Far Clip Plane value.

farclipplane

Instead of – or in addition to sculpting you can also use the Texture deformer to add roughness to the ground. With a subdivided plane selected go to > Deform > Texture. In the Attribute Editor increase the Strength to 10. Click on the Texture checkerboard icon and in the Create Render Node popup choose a Maya > 2D Texture > Noise node. Fractal, Simplex Noise and Mountain works also or you can choose the file node and link a height map (download here).

texturedeformer

I was after a kind of extraterrestrial landscape and ended up with these noise settings.

noisesettings

You can deform surfaces also with displacement shaders during rendertime with the disadvantage that the distance between displaced surface and other objects cannot be seen in the viewport. It is more memory efficient and useful for rendering surfaces like water.

Continue with Maya & Arnold Part 2 – Skydome Lighting and Background

Maya & Arnold 2017

By Maya, Rendering, Shaders & Texturing

With this multi part tutorial you can learn how to properly set up a Maya project with image based and 3-point lighting, how to create texture shaders, how to work with Cameras and render single different passes (AOVs) for compositing.

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1 Setting up a Project in Maya
2 Setting Up Skydome Lighting and Background
3 Three Point Lighting
4 Camera / Depth of Field Blur
5 Sequence Rendering
6 AOVs
7 Texture and Normal Mapping
8 Displacement Mapping
9 Creating Ocean Surfaces with the HOT Plugin for Maya and Arnold
10 Texturing with the Substance plugin in Maya and Arnold
11 Rendering with the Volume Shader