Curve guide force field does not effect smoke properly #44576

New Issue

Kalcifer Kandari · 2015-05-01T12:51:11+02:00

Kalcifer Kandari commented

2015-05-01 12:51:11 +02:00

System Information
MacBook Pro (17-inch, Mid 2010)
Processor: 2.66 GHz Intel Core i7
Memory: 8 GB 1067 MHz DDR3
Graphics: NVIDIA GeForce GT 330M 512 MB

Blender Version
Blender 2.74
Blender 2.73a

Short description of error
'Curve Guide' force field behaves in the same way as the 'Force' force field when used as a 'Smoke Field Weight' on smoke domains. Instead of flowing along the curve in a similar way to particles, smoke flows away from the origin of the curve.

Also note that none of the 'Curve Guide' settings change anything about the simulation, including the smoke domain 'Curve Guide' smoke field weight (unless it is set to 0).

Example File

A .blend file has been included that demonstrates how the curve guide should work as demonstrated with a particle system (1), then how it actually works with smoke (2), then the comparison that shows the curve guide behaves in the same way as the 'Force' force field (3) (where the 'Strength' of the field is set to 10).

smoke_curve_guide_example.blend

Exact steps for others to reproduce the error

Open blender with factory start-up file
Add -> Mesh -> Cube
Object -> Quick Effects -> Quick Smoke
Particles -> New
- Emission
  - Number -> 50
  - End -> 1
  - Emit From -> Volume
- Physics -> No

Physics -> Smoke -> Flow

- Flow Source -> Particle System
- Particle System -> ParticleSystem
- Temp. Diff. -> 0

Add -> Force Field -> Curve Guide (adjust in edit mode to create curve)
Object -> Group -> Create New Group
Select 'Smoke Domain' cube
Physics
- Smoke
  - Density -> 0
  - Temp. -> 0
- Smoke Field Weights
  - Effector Group -> Group
Play animation

**System Information** MacBook Pro (17-inch, Mid 2010) Processor: 2.66 GHz Intel Core i7 Memory: 8 GB 1067 MHz DDR3 Graphics: NVIDIA GeForce GT 330M 512 MB **Blender Version** Blender 2.74 Blender 2.73a **Short description of error** 'Curve Guide' force field behaves in the same way as the 'Force' force field when used as a 'Smoke Field Weight' on smoke domains. Instead of flowing along the curve in a similar way to particles, smoke flows away from the origin of the curve. Also note that none of the 'Curve Guide' settings change anything about the simulation, including the smoke domain 'Curve Guide' smoke field weight (unless it is set to 0). **Example File** A .blend file has been included that demonstrates how the curve guide should work as demonstrated with a particle system (1), then how it actually works with smoke (2), then the comparison that shows the curve guide behaves in the same way as the 'Force' force field (3) (where the 'Strength' of the field is set to 10). [smoke_curve_guide_example.blend](https://archive.blender.org/developer/F168919/smoke_curve_guide_example.blend) **Exact steps for others to reproduce the error** - Open blender with factory start-up file - Add -> Mesh -> Cube - Object -> Quick Effects -> Quick Smoke - Particles -> New - Emission - Number -> 50 - End -> 1 - Emit From -> Volume - Physics -> No # Physics -> Smoke -> Flow - Flow Source -> Particle System - Particle System -> ParticleSystem - Temp. Diff. -> 0 - Add -> Force Field -> Curve Guide (adjust in edit mode to create curve) - Object -> Group -> Create New Group - Select 'Smoke Domain' cube - Physics - Smoke - Density -> 0 - Temp. -> 0 - Smoke Field Weights - Effector Group -> Group - Play animation

Kalcifer Kandari commented

2015-05-01 12:51:11 +02:00

Changed status to: 'Open'

Kalcifer Kandari commented

2015-05-01 12:51:11 +02:00

Added subscriber: @KalciferKandari

Bastien Montagne commented

2015-05-01 16:23:40 +02:00

Added subscribers: @genscher, @miikah, @LukasTonne, @mont29

Bastien Montagne commented

2015-05-01 16:23:40 +02:00

Can confirm the issue, not sure whether it’s missing feature or actual bug…

Lukas Tönne commented

2015-05-01 16:42:28 +02:00

Changed status from 'Open' to: 'Archived'

Lukas Tönne closed this issue

2015-05-01 16:42:28 +02:00

Lukas Tönne self-assigned this 2015-05-01 16:42:28 +02:00

Lukas Tönne commented

2015-05-01 16:42:28 +02:00

This is indeed an incompatible setting: curve guides only work for particles IIRC (and possibly other lagrangian systems, but seems to be a hardcoded particle hack).

The effectors system is quite messy, it mixes very different features and squeezes them into the same schema, which gives the impression that they should all work for all sim types. But curve guides work by setting an explicit position for a particle on a path along the curve. For a grid-based simulation like smoke there is just no equivalent way of affecting the sim.

If you want to achieve a similar effect (make smoke move along the curve) you can set the force field type to basic "Force" and set the shape to "Curve". This makes the force act from the closest point of the curve for every cell of the smoke sim, the effect is similar to a curve guide on particles. (Note that you may need negative strength for the example configuration to work).

smoke_curve_guide_example.blend

This is indeed an incompatible setting: curve guides only work for particles IIRC (and possibly other lagrangian systems, but seems to be a hardcoded particle hack). The effectors system is quite messy, it mixes very different features and squeezes them into the same schema, which gives the impression that they should all work for all sim types. But curve guides work by setting an explicit position for a particle on a path along the curve. For a grid-based simulation like smoke there is just no equivalent way of affecting the sim. If you want to achieve a similar effect (make smoke move along the curve) you can set the force field type to basic "Force" and set the *shape* to "Curve". This makes the force act from the closest point of the curve for every cell of the smoke sim, the effect is similar to a curve guide on particles. (Note that you may need negative strength for the example configuration to work). [smoke_curve_guide_example.blend](https://archive.blender.org/developer/F168958/smoke_curve_guide_example.blend)

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Curve guide force field does not effect smoke properly #44576

Physics -> Smoke -> Flow