This page provides information on the PhoenixFDParticleTex.

 

Page Contents

 

Overview


The Particle Texture is a 3D texture that colors the positions of each particle in a particle system. The area around each particle has soft edges and is white by default, fading to black with distance from each particle's position. This area can also use color from another texture, or even use different pieces of a texture for each particle. If a constant color is used, it can either be the same for all particle areas, or it could come from a certain particle channel - Age, Velocity, RGB, etc.

You can plug the Particle Texture in a Phoenix Particle Shader's Color Map and this way you can have different colors for each particle based on their particle channels. You could also plug the Particle Texture in a material and use it to shade the surfaces of geometry objects. If you are simulating liquid that creates a WetMap particle system over geometries, you can use the Particle Texture as a grayscale mask for a Blend material that combines a dry and wet material, so the geometry that is covered by the WetMap particles appears wet, and the rest of the geometry is dry.

 

Parameters




Source Particle System | system – Specifies the particle system that will be used. It can be any standard 3ds Max particle system, and you can pick the Phoenix Simulator or the Phoenix PRT Reader.

Render-time Only render_time – The particle texture will be evaluated only during rendering. This can help speed up simulations that use this texture. Otherwise, the texture will be evaluated during simulation and could cause loading and blending of frames, which is slow and in turn can produce warnings about missing particle ID or Age channels.

Particle Area Radius | radius – Specifies the radius of the particle area. If the PA (particle age) option is enabled and the Particle Area Radius is animated, the particle Age channel is used to modulate the radius. Note: The particle ages must be exported from the Output rollout of the Phoenix Simulator. If the particles are imported from another plugin or application, e.g. through the PRT Reader object, you must make sure to export the particles' ages from the other software.

Areas Blending Method | blending – Specifies the method for blending particles that have overlapping areas.

Equal – All particles add the same contribution to the end result.
Proportional – The contribution of each particle is determined by the bell curve value at the current distance.
Biggest – The particle with the biggest contribution determines the end result.
Voronoi – The nearest particle is used.

Blend Alpha | blend_alpha – When enabled, the alpha of the sampled color texture is blended. Otherwise, it is set to 1.

Color Intensity | amplitude, amplitude_time – The color strength in the particle area. If the PA (particle age) option is enabled and Color Intensity is animated, the particle Age channel is used to evaluate the value.

Mult. by Size | mulbysz – When enabled, the Color Intensity value is multiplied by the particle's Size channel. This option can be used when blending wet and dry materials when using WetMap particles (when Wetting is enabled in the Dynamics rollout) because the WetMap particles shrink with time.

Color Map | map – Specifies a texture map connected to the particles. The contribution of each particle is the color from the texture in the Particle Area Radius, fading to black with soft edges or blending with overlapping particle areas using the Areas Blending Method. If no texture is specified, the particle area is white.

Shift Color Map | shift, shift_mode , shift_time – Enabling this option changes the calculation algorithm. Instead of contributing to the resulting colors, the particles instead produce shifted coordinates for the texture specified in the Color Map slot. When the simulation starts, each particle relates to a pixel on the texture, and also to a number of pixels around it using the radius specified by the Shift Color Map number field. As the particles move, they "pull along" the related part of the texture. If PA (particle age) option is enabled, the particle Age channel is used to shift the texture rather than the particle Position. This mode has no effect if no texture is specified in the Color Map field. See the Shift mode example below for more information.

Color From Particle Channel colfrompartchan – When enabled, the particle areas are colored using a specified particle channel of the connected particle system, such as Age, Size, Velocity, Position, etc. Note that if the particle channel is a vector channel, such as RGB, Position and Velocity, it can directly be shown as color in each particle area, but if the channel is a scalar such as the Size, Age or ID of the particles, it will produce grayscale color, unless you use the Remap Color option.

 The '...' drop-down button will only provide as an option the Particle Channels (e.g. RGB, ID) available for all files of the cached sequence.

Remap Color partcolremap – This option remaps a different color for scalar particle channels such as the Size, Age or ID of the particles, or a component from vector particle channels such as RGB, Position, or Velocity. For example, you can remap the particle Age which ranges from 0 (black) for newborn particles to several tens or hundreds (seconds), to a gradient from blue color for newborn particles to red color for old ones, by placing the blue color at position zero in the color gradient and placing the red color at a value that is the maximum particle Age (in seconds). You need to know the value ranges of the particle channels in order to remap them correctly - e.g. Age is in seconds for Phoenix particles, Size is in voxels, Velocity is in voxels/sec, etc. When remapping vector channels, you have to set the Use Color Component option to one of the vector components of the channel.

Use Color Component remapcolcomp Specifies the vector component of channels such as RGB, Position, or Velocity to be used when remapping.

     X – Uses the X axis of positions or velocities, or the Red channel from RGB color.
     Y – Uses the Y axis of positions or velocities, or the Green channel from RGB color.
     Z – Uses the Z axis of positions or velocities, or the Blue channel from RGB color.
     Length  Uses the length of the particle channel. Can be used with the Velocity channel when you need to remap the Speed of the particles to colors. If X, Y or Z are used with Velocity, this will remap the Speed respectively in the X, Y or Z directions.

The Remap Color gradient stores its parameters with the partcolor_ppartcolor_c and partcolor_i script names.

You can render out the Color From Particle Channel as a separate render element by using the Phoenix Particle Texture as an input for the VRayExtraTex render element and turning on Render as Geometry in the Particle Shader's options.



Setup for shading dry and wet materials


The Particle Texture can be used to blend between two materials. The examples below illustrate setups when using the default Scanline Renderer or V-Ray for 3ds Max. When using the Scaline Renderer, the Particle Texture is set as the Blend material's Mask. When using V-Ray, two different V-Ray Materials are set as the Base Material and Coat Material of a V-Ray Blend Material. The Particle Texture node is set as the Blend map.

This setup can be used when rendering the Wetmap particles of the Phoenix simulation. You can use a Particle Texture to read the Wetmap particle system and then blend between two materials - a dry and a wet one.

 

 

Using the Scanline Renderer

Using V-Ray for 3ds Max