Frequently Asked Questions

Have a problem that's perplexing you with Modo? It's likely others have had the same problem. This appendix lists some of the most common questions about Modo. If your question isn't answered here, review the documentation and the release notes, or contact Foundry customer support for help.

Accuracy

How do I find out my model's dimensions?

Absolute dimensions for the overall bounding volume of any selection can be found using the Dimension Tool under View > Dimensions Tool, and described inUsing Utilities. Invoking the command displays the values over a ruler, displayed directly in the 3D viewport. To confine the display to a specific section, simply select it using the appropriate selection mode, described in Selecting Items. When nothing is selected, the Dimension defaults to the overall bounding box volume of all visible items.

How do I scale my model to a certain size?

You can scale objects, based on the selection's bounding box volume using the Absolute palette, found at the bottom of the Snaps and Precision Palette tool. Use the Grab Size command to find the current size, then enter the new value in the appropriate input field, and press enter to apply the new dimension.

How can I snap items in a scene?

Modo has a snapping function that is based on the snapping of tool handles. Proper snapping requires an understanding ofSpecifying Action Centers and Falloffs settings. The snapping functionality is covered under Applying Snapping in the Modeling section.

Alignment and Positioning

How can I accurately align my object onto the surface of another object?

For simple geometry in the same item layer as the target surface, you can use the Tack tool with the Move Connected Vertices command enabled. For more complex objects, it's easier to use theHierarchy functionality found in the Animate interface tab. Both the source and target need to be separate item layers.

You can set the Center of the source item to the appropriate position in relation to the geometry, typically using the command Edit > Center to Bounding Box > Bottom.

Set the Drop Action function to the Place and Align option.

Without any tools active, simply click on the source mesh and drag it over the target surface.

Release the mouse button, setting the object to the surface.

I can't get a background constraint to work, how should I set it up?

Background constraints need some background geometry. The target geometry needs to be in the foreground, meaning in thelayer is visible and selected in the Item List. If you're not familiar with foreground, background, and visibility states, please reference the Items List. To enable a background constraint:

Press the F11 key and choose Background from the Constraint Mode options.

By default, the background constraint only constrains tool handles.

To constrain geometry as well, choose either Screen Axis or Vector options under Geometry Constraint in Tool Properties.

How can I specify specific positions for elements?

This is dependent on the particular selection mode. While in Items selection mode, you can define the position of individual layers in the Items properties panel. This sets the center position to the specific location with the associated geometry remaining in proper relation to the center element. Individual vertices can be explicitly positioned in the Info and Statistics viewport. For Edges and Polygons, transforms are applied as an offset from the present position using the Move tool. To assign a specific position, simply center the selection prior to applying the offset.

How can I tell what size my object/selection is?

Refer to How do I find out my model's dimensions?

Animation

My Item isn't rotating/scaling from where I want it to. How can I fix this?

This is most likely because the Center isn't positioned correctly in relation to the geometry. You can use the Center to Bounding Box commands to easily reposition the Center or simply Center the geometry using the appropriate command.

Why don't my deformers show up?

You can define how [MDD, Morph and Weight] Deformers display on a per-viewport basis. By default, most viewports are designated to not display animated deformers (only the Animation and Rendering interface tabs do). You can open the options panel for a particular viewport by hovering the mouse over the target viewport and press O on the keyboard. On the viewport options pop-over, you need to set the Enable Deformers option at the bottom of the Drawing and Control section. If they still aren't working, after doing so, make sure that you are working in Items selection mode when adjusting the deformer values.

Documentation

Why does Internet Explorer give me an error every time I open the documentation?

For security purposes, Internet Explorer disables the execution of scripts that are served locally (from your local system, not the Internet). If you are viewing the documentation from your local drive, you need to Allow Blocked Content each time the documentation is accessed. Advanced users may wish to enable the Allow Active Content to Run in Files on My Computer setting in the Advanced Internet Options dialog.

Interface

How can I customize my interface?

You can customize your interface easily but, before doing so, understanding the functions of the Thumb and Widget are essential. Those functions are covered under Using Layout Controls. Additionally, you can follow a walk-through for building a custom interface under Customizing Your Layout.

How can I map my own keyboard shortcuts?

Keyboard shortcuts can be assigned within the Input Editor found in the menu bar under System > Input Editor. An easier way to accomplish the same task is to utilize the Command History viewport. To map a command to a custom key:

Perform the command in Modo by either invoking it from the menu bar or within the Modo UI itself.

Within the Command History viewport, locate the appropriate command. Right-click the command and choose the Map Command to Key option from the contextual menu.

This opens the Key Assignment dialog where you can define the particular key you want to use.

Press OK to set the new definition.

You should note that this new value is saved in the Modo configuration file (MODOXXX.cfg). Removal of this file also removes custom keyboard shortcuts.

How can I change my viewport colors?

Viewport colors are changed in the Preferences (on Windows: System > Preferences, on Mac OS: Menu > Preferences) under Display > Colors. For more information on display preferences, refer to Display Preferences. You can modify the colors and then use the Save to Scheme button and assign a new name to the color scheme.

To apply the scheme to a viewport, you need to click within the target viewport to select it. Selected viewports are denoted by the orange highlighting of the Thumb icon. Then, in the menu bar, select the command View > Viewport Color Scheme and choose the named scheme defined earlier in the Preferences.

How can I change the default lights in the 3D Viewports for modeling?

Modo offers you the ability to adjust the default lighting in 3D Viewports using the options found in the menu bar under View > Edit Viewport Lights. Once the function is active, you can click and drag in the viewport to change the current light's position. Additional properties are available in Tool Properties for Color and Intensity. The option Current defines the particular light being edited. You can use the commands View > Add Viewport Light and View > Remove Viewport Light to modify the number of lights visible.

Why does my 'X' keyboard shortcut not work?

Certain keyboard shortcuts require Modo to be in a specific state or mode. For example, the Timeline shortcuts require Modo to be in Items selection mode, or the brush tip pie menu requires a Paint tool to be active. Make sure the proper tool is selected and the correct selection mode is active before applying the keyboard shortcut.

After I've changed an option, how can I return its setting to the default value/state?

Each animate-able attribute value is preceded by a small dot or circle that defines its keyframe status. You can right-click on the option to open the contextual menu and select the Remove All option returning any attribute back to its default state.

Modeling

What is a bounding box?

The bounding box is the virtual rectangular volume encompassing all the geometry in any Mesh Item layer, defined by the maximum and minimum vertex values on all three axes.

What size should I make my object?

In most cases, models are best created at real-world scale. The way lighting attenuates in a scene is all based off real-world values. To get the most realistic results, building to the correct size produces the best results. However, there are situations where working to scale has benefits, such as when modeling anything smaller than a few millimeters in size, when the model should be scaled up, or anything larger than a few city blocks should be scaled down. Items beyond these sizes push the boundaries of Modo's accuracy. You definitely don't want to be modeling sub-atomic particles or entire planets to actual scale.

How do I insert an image into my viewport for modeling?

Users can insert custom background images into a viewport using the Backdrop item added in the Item List viewport. Within the Background items properties, specific images can be applied and the settings determine how it's displayed in the 3D viewport. For more information, please refer to Modeling with Images.

How do I change the default behavior for a tool?

By default, tools should remember their settings between uses, so that the last-used settings become the default. If you want to change the system default values for a tool this can be done within the Tool Pipe viewport. With the tool active, and the appropriate new settings defined, right-click over the command name in the Tool Pipe and choose the Save Preset option. Keep the default name value in the resulting save dialog to overwrite the default behavior. Make sure only the tool you want to modify is active. Any additional Action Center and falloff settings are included if also active.

Why do my OBJ files import as all triangles? Why can't I edit my imported OBJ file?

Modo has an option to import .obj files as a Static Mesh Item, which makes it much easier to deal with multi-million-polygon objects. This option limits the modifications available to only Items mode transforms. However, the process also triangulates the geometry when generating the Static Mesh from the imported geometry. If you want to further modify imported .obj files, you should make sure this option is disabled (the default state) before importing any .obj format geometry.

When I duplicate an object it changes size, Why?

Understanding the difference between Modo's Component and Item selection modes is very important to successfully using Modo. If you aren't sure of the differences, you can read more about it under Understanding Items vs. Components. What can often happen is that an item layer is accidentally scaled while in Items mode without realizing it. Subsequent duplicates then default to the zero base transform values, thus changing the size of the duplicated objects. If this happens, you can use the Freeze > Scale option in the items properties panel before duplicating the item layer.

Why are my Replicators positioned away from the Point Source when I assign the Prototype?

Replicators base their position information in relation to the Prototype's Center position. If the geometry was created at an arbitrary position away from the Center, you can use the Tools and Commands to easily reposition the Center, or simply use the Center Commands to center the geometry.

Shading/Rendering

Do I still need to de-gamma my images with Color Management?

No, color management completely eliminates the need to remove gamma from images; this is done automatically in the background. Gamma settings are still present for image adjustment purposes, but should mostly be left at the default 1.0 value. For more information on Color Management, please see Color Management Overview.

I can't get Color Management to turn 'on' when opening older Modo scenes?

To ensure 100% compatibility when rendering older scenes, Color Management is disabled automatically. If you want to manually enable it, the Gamma setting on all image maps needs to be returned to 1.0, as well as the output gamma on the Render output. Selecting the Scene item (the clapper board icon at the top of the Items list), define a color control in the OCIO config section, such as Nuke Default. Then, under the Default Colorspace settings for each bit-depth, define the appropriate colorspace, as these settings are then applied to the images in the scene. For more information on Color Management, please see Color Management Overview.

I've applied some preset materials to an object but when I duplicate it, the clone is just gray. Why does this happen?

Material Presets default to limiting their application to a single Mesh Item, by way of an Item Mask. Disabling the Item mode masking function in the material Group item alleviates this problem. Simply change the item name listed under the Item to (all) to resolve the issue, allowing the textures to globally affect the scene.

How can I get rid of those terrible splotches in my render?

Splotchiness is generally an indicator that the number of Irradiance Rays is too small to accurately depict the surrounding environment when calculating Irradiance Caching. Try increasing the value to better capture the surrounding lighting. Lowering the Irradiance Rate, and increasing the Irradiance Ratio, can also help in certain scenes. Enabling the multi-importance sampling within the global illumination settings can also help to increase the sampling quality of Irradiance Caching global illumination.

Why is my 'X' surface so noisy in a final render?

Noise that is confined to a specific area, be it a shadow, a reflective surface, or a transparent object, is typically the result of the number of samples related to that particular option. Modo offers an extremely flexible shading solution, providing you the ability to adjust the number of rays used to calculate individual effects. The default values provide speedy renders but, on occasion, don't provide enough sampling latitude to produce smooth results.

Lights that generate soft shadows individually have a Samples setting that, when raised, increases overall rendering quality. The Material item offers a Samples setting when rendering soft reflection, as does the Refraction Roughness setting. Volumetric light does as well. When trying to reduce noise in a scene, typically there is some investigation required to determine the likely culprit. Noise related directly to shading can be reduced by adjusting the Shading Rate, while noise produced by geometry, such as using Replicators of fur, can be reduced by increasing the amount of anti-aliasing.

Note: Keep in mind that when increasing these settings, render times are likely to increase as well.

Why, when I add a Replicator, do my Irradiance pre-pass times go through the roof?

When rendering lots of very tiny details, using Global Illumination, the default calculation method, Irradiance Caching (IC) calculates the irradiance value every time a surface normal changes. When there is a lot of detail due to Replicators, Fur, or Displacements, the expensive IC calculation takes much longer to generate. You should assign affected surfaces to use the less-expensive Global Illumination option Monte Carlo. To do this:

Create a Selection Set of all the affected geometry.

Add a Material Group item to the Shader tree and place it above the Base Shader item.

In the Material Group properties, set the Polygons Tag Type to Selection Set and under Polygon Tag select the previously created Selection Set.

Add a Shader to a new Material Group by navigating to Add Layer > Special > Shader and, in the Shaders Properties, set the Indirect Illumination Type to Monte Carlo.

Fur, by default, utilizes Monte Carlo shading. The Fur Item has an option Use Irradiance Cache that disables this behavior.

My scene won't render. What can I do?

The number one reason Modo usually fails to render a scene is that it has run out of available memory. Often times this is because of too many polygons. To reduce the memory overhead, try:

• Reducing the number of subdivisions for Subdivision Surfaces geometry in the Item properties panel for certain high resolution objects.

• Disabling Adaptive Subdivision and setting the subdivision level manually for each item.

• Setting the Displacement as Bump option (if using displacement), enabled in Render items under Settings, and reducing the number of subdivisions.

The resulting image has far fewer polygons but is visually similar to the higher-level render.

• Removing fur outside the camera view on fur items by using the Fur Frustrum Culling option.

If there are no reflective surfaces in the scene this can be a huge memory saver.

Other options include rendering multiple Limited Region sections and assembling them in an image editor.