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Allows you to switch the interface from basic to expert mode and vice versa.
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Material density, particle concentration.
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Scattering Albedo (Base mode only)
Only in basic mode. Determines how much of the total fade is the scattering component.
Adjustable by base weight, color, spectral spline and texture map. The "At distance" value determines the average penetration depth of the beam into the material before it hits the particle.
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For basic mode: determines what color should be obtained from the initially white beam at a given distance (At distance).
Adjustable by base weight, color, spectral spline and texture map. The distance value is set in the current distance units in the scene.
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For expert mode: sets the sigma value for absorption.
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Scattering (Expert mode only)
For expert mode: sets the sigma value for scattering.
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1. Henyey-Greenstain (Anisotropy): classic scatter function, simple and fast. Well suited for most applications, with the exception of spectral rainbow effects.
- Anisotropy: Non-uniformity of light scattering on a particle. It varies from -1 to 1. Negative values scatter mostly backwards, positive ones scatter forwards. A value of zero gives symmetric spherical scattering. Adjustable by base weight, color, spectral spline and texture map.
2. Mie scattering: physically correct scattering by large particles using long calculations in accordance with the theory of electromagnetic scattering by Mie. Very slow for large particles. It is recommended to use only for spectral effects.
- Diameter: particle diameter in microns. A good rain rainbow requires particle sizes of 100-300 microns.
- IOR: refractive index for particle material. Spectral effects require specifying a spectral spline.
- IOR-K: imaginary part of the refractive index, responsible for the conductive properties of the particles.
- Gain: non-physical parameter that increases the brightness of the rainbow. If the rainbow hits a bright background, then its visibility can be improved by this factor.
- Spread: In nature, it does not happen that all drops have exactly the same size. In the laboratory, this can be done and get rings of secondary rainbows. In nature, it is difficult to notice even a second rainbow, although up to 15 rings were obtained in the laboratory.
This setting brings chaos to the size of the particles and makes the rainbow look more natural.
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Sets the brightness and color of particle emission. Important: the square of this value goes into rendering, which allows you to have a large dynamic range of brightness.
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Sets the particle emission temperature in Kelvin.
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Allows you to distort texture coordinates before sampling texture maps. Value - offset value and additional coefficients for X Y Z axes.
Example: Fireball modeled with a spherical gradient and three Perlin Noise maps for density, temperature, and displacement.
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The material of the boundary within which this Dali Volumetric is defined. For example, for sea water, the boundary should be dielectric (
Dali Physical), and the content, if any, should be
Dali Volumetric.
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With this option, all coordinates for texture maps will be mapped to an interval from -1 to 1. I.e. coordinates in model space during tracing will take such values as if the bounding box has a size from -1 to 1. This will allow not to update the transformation matrices and texture coefficients when the model is scaled. However, the "At distance" values may need to be corrected as the density of the material will not change.
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Enables a simplified tracing mode, when the ray does not change its direction inside the material and the volume has only one scatter event.
This mode gives a cleaner picture, but there is a slight loss of energy. Recommended for rendering light rays in fog (Light Shafts).
Currently, Dali Renderer is not able to mix Single Bounce and Multi Bounce volumes. If they are mixed, artifacts are possible.
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Forces Dali Renderer to make at least one sample in the volume, does not allow the beam to directly pass through the volume. This option is useful for geometrically or optically thin volumes. Such volumes are characterized by increased noise, which this option is designed to eliminate. The disadvantage of the option is that less attention is paid to objects behind the volume, they can be rendered with more noise than without the option.
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Converts emitting volume to emitter for efficient sampling. Works only with non-uniform volumes (if using VDB file or texture maps). Requires some preprocessing time to prepare the scene before rendering.
Example: ball lightning (fireball) indoors. 256 samples per pixel.
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If there are local light sources inside or near the volume, then this parameter sets the probability of executing a special sampling algorithm, taking into account the presence of such sources. This setting is not useful for distant sources or the Sun & Sky model. A value of 0.5 is a good compromise. If it is known for sure that there are no such sources (for example, under water), then set the value to 0.
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Material priority in a system of nested dielectrics and volumes.
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The size of the optimizing structure for sampling inhomogeneous volumes (which are obtained from a VDB file or if using texture maps).
Too small size reduces rendering efficiency and quality, too big slows down scene preprocessing and may cause artifacts. Values of 6-7 usually give the best results.
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Specifies the precision of the optimization structure representation. The lower the value, the more accurate. The default value is usually fine.
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Specifies the interval of the spectrum on which the spectral splines are defined.
