--- title: "Rendering Rollout" canonical: "https://documentation.chaos.com/space/VMAX/113575445/Rendering%20Rollout" format: markdown --- This page provides information on the Rendering rollout. ## **Overview** --- For convenience, the shading and rendering of Volumetric effects (Render Mode: Volumetric, Volumetric Geometry, and Volumetric Heat Haze) are handled by the built-in Volumetric shader of the V-Ray Volume Grid. All parameters necessary for rendering a Fire / Smoke simulation can be found under the Rendering rollout and its sub-rollouts.  The Volume Grid is able to operate in multiple rendering modes that can be divided into two main branches: volumetric and surfaces (Isosurface, Mesh, Ocean Mesh and Cap Mesh). The volumetric modes are used for fire and smoke. Maya materials can't be used to shade volumetrics, so their shading is described in the [Fire](https://docs-chaos.atlassian.net/wiki/spaces/VMAX/pages/113586720), [Smoke Color](https://docs-chaos.atlassian.net/wiki/spaces/VMAX/pages/113586716) and [Smoke Opacity](https://docs-chaos.atlassian.net/wiki/spaces/VMAX/pages/113586728) rollouts. The surface modes can be used for some interesting fire-related effects, like freezing flame or cartoon-style smoke. Unlike the volumetric modes, surface modes have no dedicated shader; they use the material applied to the Volume Grid. The V-Ray Volume Grid also provides you with the option to generate a mesh surface based on any of the supported channels. Thus, a Smoke simulation can be rendered as a polygon mesh with a custom material applied to it. > ✅ For a list of supported Render Elements, please check the  [V-Ray Render Elements Support](https://docs-chaos.atlassian.net/wiki/spaces/PHX4MAX/pages/124363038) page. > ✅ > ✅ You may also check the [Volumetric Rendering In-Depth](https://docs-chaos.atlassian.net/wiki/spaces/VMAX/pages/113575251) guide for tips on speeding up the rendering of volumetric effects with V-Ray.
UI Path ||Select V-Ray Volume Grid|| > **Command panel** > **Modify **tab > **Rendering** rollout ![3dsMax_VGrid_RenderingRollout_UIPath.jpg](media://d945d08e-7392-429c-905a-4dd86915d815)
## **Parameters** --- > Macro (anchor) > Macro (anchor) --- ### **Example: Step %** This example shows how the **Step %** value can be used to improve the quality of the ray-marching. The Step % value is set to 50 for the first image, and 150 for the second image. ## **Surface Channel** --- This section controls the conversion of the grid content into geometry. If **Mode** is set to **Mesh**, **Ocean Mesh**, **Cap Mesh** or **Isosurface**, the **Surface** channel needs to be set and an appropriate **Isosurface Level** must be chosen from this section. The controls in this section also denote the surface used in **Gradient** and **Surface-driven** displacement. This way it can affect all render modes, not just the surface modes. The technique for generating the surface is based on the [isosurface](http://en.wikipedia.org/wiki/Isosurface) concept. The resulting surfaces are mostly used to render liquids, but can be used for smoke and fire as well to create effects like underwater bubbles, freezing fire, etc. ## **Ocean** --- > Macro (anchor) --- ### **Example: Ocean Subdivisions** The following example shows how increasing the **Ocean subdivisions** twice makes the vertices count to grow four times: ## **Motion Blur** --- To render your simulation with Motion Blur, make sure that your cache files contain a **Velocity** field and that it is properly remapped to the internal V-Ray Volume Grid Velocity channel in the **Input** > **3rd Party Channels Mapping** dialog. > Macro (anchor) --- ### **Example: Volumetric Motion Blur for Fire** ### **Example: Volumetric Motion Blur for Explosions** --- ## **Mesh Smoothing** --- ## **Displacement** --- Displacement is a technique intended to add detail to the simulation during rendering. The idea of the Phoenix displacement is similar to the usual geometry displacement: a texture is sampled, and the corresponding point of the fluid volume or surface is shifted in a direction at a distance determined by the texture. You can plug any V-Ray, 3ds Max or Phoenix texture maps. You can use the Phoenix FD Simulator's Mesh Preview option to check how the attached displacement map is affecting the surface when **Mode** is set to **Mesh**, **Ocean Mesh **or **Cap Mesh**. > Macro (anchor) --- ### **Example: Surface Driven vs. Vector Displacement** > Macro (anchor) --- ### **Example: Advection** > Macro (anchor) --- ### **Example: Advection Displacement Maps** --- ### **Example: Volumetric Displacement** A grid with 24 million cells with applied displacement. This resolution is not enough by itself for a convincing result.