Common Issues

From Fracture FX
(Difference between revisions)
Jump to: navigation, search
(Using the plug-in)
(​ Should I scale units like mass and gravity depending on my Maya units?)
Line 35: Line 35:
  
 
===​ Should I scale units like mass and gravity depending on my Maya units? ===
 
===​ Should I scale units like mass and gravity depending on my Maya units? ===
Units can be whatever you want them to be. The only unit that's fixed is in Fracture FX is time (seconds). If you decide the numbers for distance you use represent meters, then gravity is meters-per-second-per-second (ms^-2). and if you decide your mass is kg, then your impact force becomes newtons, and so on. It's all linked. if you scale up the scene, i don't think you'd have to change the mass, but I'd have to check.This shouldn't really matter that much, since mass doesn't affect how fast something falls anyway.​​
+
Units can be whatever you want them to be. The only unit that's fixed is in Fracture FX is time (seconds). If you decide the numbers for distance you use represent meters, then gravity is meters-per-second-per-second (ms^-2). and if you decide your mass is kg, then your impact force becomes newtons, and so on. It's all linked.
  
 
=== The simulation sometimes explodes immediately with Bullet ===
 
=== The simulation sometimes explodes immediately with Bullet ===

Revision as of 05:03, 26 November 2013

Contents

Installation

Bullet doesn't load

If you see the error "initializePlugin function could not be found in plug-in (bullet)", then the bullet plug-in is not installed correctly. It should remain inside the fracture_plugins directory, since it is a plug-in to fracture, not a separate plug-in to Maya. fracture_plugins should be placed alongside the fracture.mll/.bundle/.so. Once it's in the correct directory, bullet can be loaded from under the solver globals in the Edit Simulator window. See Installing the plug-in for more information.

What do I do with the devkit folder?

You can ignore the devkit folder, it does not need to be installed to use the plug-in. The devkit is intended for developers at larger studios who wish to connect an in-house solver.

Fracture doesn't load on the Mac

If you see this error:

// Error: line 1: Unable to dynamically load : /Users/Shared/Autodesk/maya/2013/plug-ins/fracture.bundle
does not match the current architecture //

then the file is likely corrupted, and is not being identified as a 64-bit bundle. Reinstall the plug-in from the zip archive you downloaded.

Using the plug-in

There's a large pyramid when I break something

The object has to be closed, manifold (edges have no more than 2 adjacent polygons), with outward-facing normals, and no self-intersections.

The scene is slow when I rewind or locks up when I connect a large object

Increase the 'point separation' before connecting it. This is a world-space sampling distance used to convert all objects to a point-based representation. (Enable 'Draw points' to see the point cloud.)

The sim looks wrong after baking to keys, objects are far apart

Make sure the scene units are centimeters. Other units are currently not supported.

The simulation sometimes explodes using the internal solver

Set a velocity limit. Use the numeric display (before or after baking to keys) to find a sensible maximum value.

​ Should I scale units like mass and gravity depending on my Maya units?

Units can be whatever you want them to be. The only unit that's fixed is in Fracture FX is time (seconds). If you decide the numbers for distance you use represent meters, then gravity is meters-per-second-per-second (ms^-2). and if you decide your mass is kg, then your impact force becomes newtons, and so on. It's all linked.

The simulation sometimes explodes immediately with Bullet

Change the shape class to btGImpactMeshShape. Sometimes bullet has problems dealing with collision between convex and non-convex objects.

I cannot animate things without the solver running

Uncheck active on the simulator globals tab.

Deformable collision objects don't work with Bullet

These are only supported by the internal solver.

Are events tied to particular objects?

No, by design events can break any number of objects, at different times and with different break properties per object. Some events may not break anything, and may only modify the dynamics properties or the custom attributes carried by objects. You can however choose to restrict events to particular objects using the object filter, or groups of objects using the object_set filter. Events are meant to be customisable. See Events and filters for more information.

Keyframed objects won't break when they collide

Make sure they're both connected to the simulator. (They're connected if they're listed under the inputs tab, and still appear in the viewport when you switch off the display of polygons.) If both objects are keyframed, also make sure 'passive collide' is enabled in the solver globals, otherwise the simulator will not check for collisions between two passive (non-simulated) objects.

How do I change the animation of a passive object?

Disconnect it from the simulator using the button on the inputs tab. Change the animation. Reconnect it.

How do I animate cracks?

The breaking pattern produced by the voronoi/split-plane/crack-image fragment modes cannot be animated. You can only animate a mask applied to that pattern, in the form of an animated texture sequence, animated procedural texture or ramp, or an animated/deforming volume. Set the localize mode to event-driven, and connect a texture or volume. Alternatively, choose Add event -> Animated -> Texture driven, from the menu under the events tab. In any case, you may want to uncheck the active flag on the simulator while keyframing, in order to stop the solver evaluating when you jump around the timeline.

If you don't need to see partially growing cracks inside an object, a faster alternative to the localize mode is to create an event that breaks the entire object on frame 2, but leaves the fragments passive (activate-on-break = off). Then activate the objects that touch an animated/deforming volume from a second event, e.g. Add event -> Animated -> Activate in volume.

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox