houdini烟火中文帮助.doc

Pyro SolverSets and configures a Pyro solver. This solver can be used to create both fire and smoke.The Pyro solver is an extension of the Smoke Solver. If you just want to generate smoke without combustion (flames), you might consider using the Smoke Solver since its a little simpler, however the Pyro solver is more flexible.See how to use the Pyro tools for information on creating simulations using the shelf tools. See Pyro look development for information on using the parameters to achieve different flame and smoke looks.Setting upIf you use the shelf tools to create Pyro effects, they will set up the sourcing, solver, and output object for you automatically.If you are setting up a pyro network from scratch, you can use the Smoke Object node to create a DOP object with the data required by the Pyro solver already attached. If you already have a DOP object, you can use the the Smoke Configure Object node to add the necessary data to it.This solver makes use of various field subdata on the object.The object should have a scalar field density for the density of the smoke.The object should have a vector field vel for the velocity at each voxel.Optionally, the object can have a scalar field temperature for internal buoyancy calculations.Inputssmokesolver#object_inputsmokesolver#presolve_inputsmokesolver#velupdate_inputsmokesolver#advection_inputsmokesolver#sourcing_inputParametersSimulationThese parameters control how the simulation develops over time. See how pyro simulations work for information on how the temperature and velocity fields drive the simulation to a great extent.Time ScaleRest场怎样快的根据Velocity场移动。数值1意味着Rest场准确匹配Velocity场，然而这容易产生条纹状的效果。设置低于1的数值时，Rest场会比实际移动的慢，不过可以减少条纹状的效果。Temperature DiffusionA Guassian blur factor on the temperature field. Higher values spread the temperature out more and create a less sharply defined effect and more cooling. For example, a value of 2will blur the temperature field by a radius of 2 every second.这个参数是在温度场上的高斯模糊因子。高的数值使温度扩散的更多，得到不尖锐的效果，并且冷却的会更快。例如，设置数值为2时，以每秒半径为2的单位模糊温度场。(The real-world motivation for this parameter is to simulate turbulence at a finer scale than the sims resolution, which spreads the field out.)模拟真实世界的运动时，设置良好的扰乱会比设置更高的解算精度重要，可以使场得到良好的传播。Cooling RateHow fast the temperature field cools to zero. A value of 0.9 will decrease the temperature of hot gas by 90% (to 10% of its original value) every second.这个参数控制温度场怎样快的冷却为0，0.9的数值将会每秒减少90%的热气。Warning This is the inverse of the Cooling Rate parameter in Houdini 11 and lower versions.ViscosityThe “fluid-ness” of the velocity field. Higher values make neighboring voxels have the same velocity, creating a more flowing look. A value of 0 allows adjacent voxels to move any direction without resistance, creating a more chaotic, turbulent look.速度场的流动性，高的数值可以使相邻的voxel有同样的速度，得到更加跟随的效果。数值为0允许相邻的voxel速度没有抵抗的朝向各个方向，得到更加无序的，扰乱的效果。(Inside the solver, higher viscosity values introduce a penalty when a voxels velocity varies from that of its neighbors. This is currently implemented by applying a diffusive term to the velocity field.)Buoyancy LiftAn upward force at each voxel scaled by the difference between the ambient temperature and voxels temperature, so hotter areas will get more lift and cooler areas will sink. Increasing this makes the effect rise faster and go higher.通过比较环境温度和voxel温度得到的每个voxel的向上的力，因此热的区域会上升，冷的区域会下降。Buoyancy DirThe direction in which buoyancy is applied. This is usually the Up direction of your simulation, but often can be altered to quickly tweak the look of a sim.浮力的方向。CombustionThe combustion model takes the fuel field and turns it into burn, temperature, and density (smoke).燃烧模式使用fuel场，并且转化到burn，temperature，density中。Enable CombustionEnables the combustion model for the Pyro Solver. If this is off, the fuel field and everything else related to burning is ignored.Ignition TemperatureThe combustion model will only occur if the temperature field is above this value. If you want all fuel to instantly ignite, use a negative value.如果温度场大于这个数值，发生燃烧。如果想使所有燃料立即点燃，可以使用一个负值。Burn RateThe amount of fuel to burn per second. This is a ratio: 0.9 means after one second 90% will be burned.每秒有多少燃料转化为burn，数值0.9意味着一秒后将有90%的fuel被燃烧。Fuel InefficiencyControls how much of the burned fuel is actually not burned, but kept 0 means all burned fuel is removed from the fuel field. 1 means that no fuel is removed from the fuel field when it is burnt.控制有多少燃烧的fuel实际上没有被燃烧，但是如果保持数值为0，意味着从fuel场中移除所有燃烧的fuel，数值为1意味着没有fuel被移除。Temperature OutputThe amount to increase the temperature field by for every unit of fuel consumed.通过每单位的燃烧消耗增加给温度场的量。This is affected by both the heat and burn fields, as per the influence parameters.这个参数同时受到heat场和burn场的影响。Gas ReleasedA scale factor controlling how much gas is injected into locations where fuel is burnt. This causes burning areas to blow outwards.一个缩放因子，控制有多少gas被注入到燃料燃烧的地方，会导致燃料区域往外吹。The gas release is scaled by both the heat and burn fields according to the influence parameters.这个参数通过heat场和burn场被缩放。FlamesOptions controlling the flames (heat).控制火焰（heat）。Flame HeightScaling factor for flames. Higher values give taller flames, lower values give smaller flames. This value is not measured in any unit (it is not the height of the flames in Houdini units), it simply affects the amount of cooling applied to the flames.火焰的缩放因子。这个参数不是Houdini的单位，只是简单的影响火焰的冷却量。Very low values will not necessarily result in very small flames, since the cooling factor will often not be enough to counteract a hot temperature field.非常低的数值不一定会得到非常小的火焰，因为冷却因子经常不足以抵消热的温度场。The inverse of this value (multiplied by the cooling field, see below) is subtracted from the heat field, so lower values give more cooling and smaller flames.You can use the cooling field controls below to vary the flame height value based on the value in a field (by default the temperature field).可以使用Cooling Field控制火焰高度是基于什么场（默认为温度场）。Cooling FieldWhen enabled, the values in the given field (by default, temperature) are used to vary the flames cooling rate across the container.勾选时，使用给定的场来变化火焰的冷却率。Cooling field rangeThe range of values in the control field to map onto cooling amounts.用于remap时冷却场的数值范围。Remap heat cool fieldThe ramps vertical axis is amount of cooling and the horizontal axis is the value in the control field. For example, the default ramps shape, which is high on the left and low on the right, applies more cooling where the temperature is low.Ramp的竖轴是冷却量，横轴是控制场的数值。例如，默认的ramp形状，高的值在左，低的值在右，那么就是温度低的地方冷却的更快。SmokeOptions controlling the emission of smoke/soot (density).控制烟的发射（density）。Emit SmokeEnables the emission of smoke/soot from burning objects.Create Dense SmokeAdds smoke to the system without considering how much smoke is already present. This is good for heavy explosions or big plumes of smoke. When this option is off, smoke is only added up to a certain maximum amount in each voxel, giving a lighter, less dense smoke.增加浓烟，而不考虑烟已经有了多少。非常适合制作重型爆炸或大的羽状浓烟，当这个选项关闭时，得到少量的烟。SourceWhere the smoke is emitted. The best choice is usually “Heat”, which is more realistic and prevents the smoke from obscuring the flames at source.在哪里发射烟，通常最好的选择是Heat，这会更加真实，以防止在源的隐藏火焰中产生烟。BurnEmit smoke at the point of flame ignition (the burn field) and nowhere else.在刚点燃的地方发射烟。HeatEmit smoke wherever the flames cool to a certain value.在火焰冷却到某个数值的地方发射烟。Smoke AmountScales the amount of smoke to be added. The base smoke value depends on the value in the field set by the Source parameter (burn or heat).增加烟量的倍增器，基础烟量依赖于设置在Source参数面板下的场的设置（burn或者heat）。Heat CutoffThe value of the heat field at which smoke is emitted. This option is only available when Source is “Heat”. For example, if Heat cutoff is 0.2, smoke appears where the heat field is 0.2 or cooler. The Blend amount parameter controls what happens above the heat cutoff point.以heat场的数值发射，只有当Source是Heat时，这个参数才有效。例如，数值设置为0.2，烟出现在heat场0.2的地方或者更冷的地方，Blend amount参数控制这个参数数值以上的地方产生烟。Blend AmountIncreasing this parameter gives a smoother fire-to-smoke transition by adding a falloff above the Heat Cutoff value. This option is only available when Source is “Heat”.在超过Heat Cutoff数值上增加烟，只有当Source选择Heat时才有效。The value controls the blend between the full amount of smoke being added at and below the Heat cutoff, and no smoke being added at the highest heat (1.0). A value of 0 adds no smoke above the heat cutoff. A value of 1 blends from adding full smoke at the cutoff point, through decreasing amounts of smoke at higher heat values, up to the highest heat.数值0意味着不增加烟，数值1意味着到最热的Heat都增加烟。FuelOptions controlling the influence of fuel.Advect FuelWhen this option is off (the default), fuel is stationary and is not affected by the velocity field. When this option is on, the fuel field as advected just like temperature, heat, and density. Turning this option on makes results more unpredictable and is also slower to calculate.当不勾选这个选项时，燃料是固定的，不受速度场的影响。当勾选这个选项时，燃料场像temperature，heat和density一样有对流。Fuel SpeedThe maximum speed at which fuel can move by advection.gas通过advection.gas使燃料移动的最大速度。ShapeThe parameters on this tab control the shape and development of the flame/smoke. All except dissipation affect the velocity field as internal forces.这个标签下的参数控制火/烟的形状和发展。除了Dissipation，其他的参数都会作为内力影响速度场。Remember that the resolution of the Smoke object determines how much detail you can get in the fire/smoke. However, the pyro solver is largely resolution independent, so you can often work in low resolution and then bump up the resolution with similar, more detailed results.Smoke Object的精度决定火/烟有多少细节，然而，pyro解算器有独立的高精度，所以可以先在低精度下测试，然后提高精度得到更多的细节。Houdini includes two different ways to add turbulent noise to fire: shredding and turbulence.有两种方法给火增加扰乱，shredding和turbulence。Shredding is the main way to add “high frequency” noise to flames. It squashes and stretches the velocity field to create the licks and flows typical of fire.使用shredding方法主要是给火焰增加“高频率”的noise，shredding压缩和拉伸速度场以产生典型的火舌和火的流动。You should use the turbulence to add “low frequency” noise: rolling, churning, large-scale motion.可以使用turbulence增加“低频率”的noise：翻滚，搅拌，大规模的动态。For each shaping parameter, there is a checkbox to turn the shaping type on, and a scaling factor to control how much of the shaping type to apply, and below those parameters are tabs containing control and visualization parameters for each shaping type.Expert users: The Pyro solver is implemented using the Smoke solver with additional subsolvers to provide Gas Sharpening, Confinement, Shredding, Turbulence, Dissipation, and Disturbance.Note You can attach additional velocity field updating DOPs such as Vortex Equalizer, Gas Wind Dop and Gas Damp Dop to the Pyro solvers second input (“velocity update”).可以结合速度场更新DOP，例如Vortex Equalize，Gas Wind，Gas Damp可以连接到pyro解算器的velocity update输入端。DissipationCauses smoke (density) to disappear over time. Low values cause smoke to disappear slowly, high values cause smoke to disappear quickly.使烟消散，低的数值使烟消散的慢一些，高的数值使烟消散的快一些。For example, a value of 0.1 means 10% of the smoke will disappear every second. A value of 1 will make all smoke disappear immediately.例如，数值为0.1意味着烟每秒消散10%，数值为1意味着所有的烟立即消散。Since this operation uses multiplication to achieve its effect over one second, the per-frame effect may be a lot less than expected. A value of 0.75, which removes 75% of the field over one second, only removes 5.6% of the field every frame (at 24 FPS). This compounds over the 24 frames to get the final desired 75% removal.See the Dissipation tab below.数值为0.75每秒将会消散75%，每帧消散5.6%的场。DisturbanceIntroduces detail of a certain size in the smoke or fire without changing the general motion or shape of the simulation.See the Disturbance tab below.在不改变一般动态或者解算形态的情况下，调整烟或火的细节。Shredding撕裂Pushes and pulls the velocity field based on gradient of the heat field to create the the streaks, separation, and “licks” typical of fire.基于heat场的梯度推拉速度场，以调整火的条纹，分离，和火舌。Very high values tend to give a random, fractal look, while very low values or no shredding gives blobby flames without much character.非常高的数值可以得到随机的效果，非常低的数值，或者不使用shredding得到没有特点的斑点状火焰。Since shredding works on the gradient of the temperature field, lower temperature diffusion results in a more noticeable shred effect. When temperature diffuses more, the gradient becomes less dynamic, resulting in bigger streaks. The higher the grid resolution, the more detailed the gradient becomes.See the Shredding tab below.因为shredding是基于温度场的梯度，所以比较低的温度扩散会得到更明显的shredding效果。当温度扩散更多时，梯度的动态将会变少，得到更明显条纹效果。更高的网格精度会得到更多梯度细节。SharpeningSharpens features in the velocity field, making smoke more wispy/streaky rather than soft/fluffy. This can be useful when youre not using much shredding, to increase the definition of the features in the flame, but oversharpening can give artifacts in the volume.See the Sharpening tab below.速度场的锐利特征，可以得到更纤细，条纹状的烟。当使用不是很多的shredding时，Sharpening非常有用，可以加强火焰的效果，但是数值过大会使效果有些假。TurbulenceAdds “churning” noise to the velocity field. You should generally use this to add powerful, large-scale/low-frequency noise and rely on shredding for smaller features. This is especially useful when you have a very fast-moving fire and you want to add more character to it.See the Turbulence tab below.给速度场增加翻腾状的noise。通常可以使用Turbulence增加大规模的，低频率的noise，使用shredding得到更小的细节。但有模拟非常快速移动的火时，Turbulence特别有用。ConfinementBoosts swirls (vortices) where they exist, increasing “curliness” in the simulation that would otherwise be lost by the grid resolution. Too high values can make the simulation unstable and blow up. Negative values suppress vortices and smooth out the simulation, but it is usually better to just use a lower resolution grid.(The Pyro solver does not use explicit vorticles, it can detect vortex locations directly in from the velocity field.)推动涡流以加强卷曲的效果。过高的数值会使解算不稳定。负值压制涡流，使解算效果平滑，但是一般最好使用低精度的网格。（Pyro解算器不使用明确的涡流，而是直接从速度场中检测涡流的位置。）You can use a ramp to remap the amount of confinement based on the curl amount, for example to apply more confinement to larger vortices.See the Confinement tab below.可以基于卷曲量remap confinement的量，例如可以给更大的涡流应用更多的confinement。DissipationControl fieldWhen enabled, the force exerted is scaled by the content of this field.通过这个场的内容缩放施加的力。Control rangeMap from this range of values in the control field.控制场的数值范围。Remap dissipation fieldThe ramps vertical axis is amount of dissipation and the horizontal axis is the value in the control field. For example, the default ramps shape, which is high on the left and low on the right, makes smoke disappear more quickly where the temperature is low.竖轴是消散量，横轴是控制场的数值。例如，默认的ramp形状是左高右低，那么在温度低的地方，烟消散的更快。DisturbanceField To DisturbThe field to apply the disturbance forces to.CutoffIgnore voxels with values higher than this in the “threshold field” (density by default, you can change the field on the Bindings tab). This lets you only affect the edges of the smoke.忽略高于“阀值场”数值的voxel（默认为density，可以在Bindings标签中改变场），这样可以只影响烟的边缘。Use Block SizeWhen this option is on, use the Block size parameter to set the size of disturbance elements in word space units. When this option is off, use Locality to control the size of disturbance elements in voxels. Using block sizes avoids issues if you scale the container.当打开这个选项时，可以在世界空间单位中，使用Block Size参数设置扰乱元素的尺寸。当关闭这个选项时，可以在voexl中，使用Locality参数控制扰乱元素的尺寸。Block SizeSize in world units of the details added. Higher values give larger disturbance elements. Available when Use block size is on.更高的数值可以得到更大的扰乱元素。LocalityNumber of voxels are sampled into a certain disturbance value. Higher values give larger disturbance elements. Available when Use block size is on.产生disturbance的voxel的数量，更高的数值可以得到更大的扰乱元素。Control settingscontrol_settingsBindingsThreshold FieldVoxels with values higher than the value of the Cutoff parameter in this field will not be disturbed.高于场中Cutoff参数数值的voxel不会被扰乱。ShreddingTemperature thresholdAt temperatures lower than this value the velocity field will be stretched, at temperatures higher than this the velocity will be squashed. Lower values give more shredding at the edges of the flame, where the temperature is lower.在温度低于这个数值的地方，速度场将被拉伸，在温度高于这个数值的地方，速度场将被压缩。较低的数值会得到更多的火焰边缘被撕裂的效果，因为那里温度低。Threshold widthThe width of an area around the Temperature threshold where squash and stretch are blended. Lower values give harsher squash and stretch, higher values give smoother streaks.Temperature threshold周边的宽度，融合挤压和拉伸。较低的数值得到比较粗糙的挤压和拉伸，较高的数值得到光滑的条纹效果。SquashHow much to squash the velocity field when the temperature is above the Temperature threshold.当温度大于Temperature threshold参数值时，挤压速度场的强度。StretchHow much to stretch the velocity field when the temperature is below the Temperature threshold.当温度小于Temperature threshold参数值时，拉伸速度场的强度。Clip gradientClips the calculated temperature gradient to this maximum value. This is useful when a simulation has very high temperatures (for example, an exploding fireball) to keep the high temperatures from translating into extreme, bizarre shredding.剪切被计算的温度梯度为最大数值。当有非常高的温度时，这个参数非常有用（例如，爆炸的火球），可以从转化为奇异撕裂的地方保持高温。Control settingsThe controls on this tab let you vary the amount of shredding across the container based on the values in a field.基于一个场中的数值，变化撕裂量。Control fieldWhen enabled, the force exerted is scaled by the content of this field.当勾选时，通过指定的场缩放受到的影响。Control influenceA scaling factor on the control fields influence on the effect. A value of 0 makes the field have no influence.缩放因子，控制场的影响，数值为0使场没有影响。Control rangeMap from this range of values in the control field.控制场的数值范围。Remap cont