Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Volumetrics are currently compatible with Maya's internal fluids and Fume FX. Further examples of customer work using Volumes can be found here.

 

There are some limitations when using them. Things to bear in mind when rendering Maya fluids:

...

Info

A tutorial that covers working with Maya fluids can be found here.

Center

Arnold fluid settings

...

The "volume samples" parameter is similar to the light's "samples" parameter for surface shading , but in the context of volumes. It controls the number of direct light samples for a ray intersecting a volume on a per-light basis, and like as the "samples" parameter for surfaces, it is also a squared number.

...

Step Size controls the rate at which the volume shader gets called. The value indicates the average distance between adjacent volume shader samples along a given ray, in world space units. Generally, you will want this setting to be as large as possible before visibly noticeable artifacts occur, and in the case of voxelized volumes no smaller than about half the size of your voxels (in world space). Low Step Sizes will increase render times. For example, when the step size is 0.1 and the volume is 10 units big in world space, there are approximately 100 primary samples and therefore the volume shader is called 100 times.

Info

The step size has a fixed size, therefore, the larger the container the more steps will be taken and the longer it will take to render. Also, beware that if the step size is too small your render times will increase. If you cannot see the rendered Fluid, you may need to reduce the Step Size value.

...

The anisotropy setting controls the "mean cosine" of any light that is scattered at a point within the volume. This is equivalent to the "g" or "eccentricity" parameter in the Henyey-Greenstein phase function. Valid values range from -0.99 (full back-scatter) to +0.99 (full forward-scatter), with 0 being isotropic scattering (the default). Volumes whose scattering consists in of relatively large/opaque particles tend to be back-scattering, while volumes whose scattering consists in of relatively small/transparent particles tend to be forward-scattering. For example, skin is highly forward scattering with a mean cosine of about 0.85. Increasing the Phase Function Anisotropy value causes light to appear more forward-scattered within the volume.

...

Specifies the filtering type when accessing the voxel grid values. "Closest" filtering is the cheapest in render time but may result in excessive blockiness in low-resolution grids. Higher-quality filtering will look smoother but take longer to render.

...

Defines how the texture coordinates are defined. "Fixed" sets the values to equal the object space coordinate system (0-1 for the volume in x,y and z). "Grid" uses a grid of points and interpolates for in-between values.

Info

Note, that Texture Color is only compatible with textures that have 3D co-ordinates such as Ai Noise.

...

Center

Ai Noise texture mapped to fluid's color and opacity texture attributes. Maya scene file here.

Info

When dragging a texture onto the 'Texture' slot, ensure that it is connected properly, otherwise, it will not render. You should see the slot hi-lighted around the edges when dragging the texture map from the Hypershade window over it as per the above screenshot.

...

Privacy settings / Do not sell my personal information / Privacy/Cookies