--- title: "Rendering" canonical: "https://documentation.chaos.com/space/VC4D/116853681/Rendering" format: markdown --- This page provides general information about the Rendering tab of the V-Ray Volumetric Grid. ## **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 roll-out 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. Cinema 4D materials can't be used to shade volumetrics, so their shading is described in the [Fire](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116853673), [Smoke Color](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116853677), and [Smoke Opacity](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116853561) rollouts. The surface modes can be used for 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. > Macro (ui-text-box) > > For a list of supported Render Elements, please check the [Render Elements](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116855112) page. > > You may also check the [Volumetric Rendering In-Depth](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116855379) guide for tips on speeding up the rendering of volumetric effects with V-Ray. ## **Rendering** --- > Macro (anchor) --- ### **Example: Step %** This example shows how the **Step %** value can be used to improve the quality of the ray-marching. The values are marked on the slider. Slide left and right to see how the smoke changes. The first render, which has a **Step %** value of **90**, took *3m 2s* to complete. The second render, with a **Step %** value of **900**, took *2m 13s* to complete. Increasing the Step % speeds up the render, but it reduces detail. --- ### **Example: Heat Haze** This example shows how **Heat Haze** adds refraction at each ray-marching step through the volume. This only affects the camera's view. Heat haze will not affect shadows cast through a volume. In this example, the **Render Mode** is set to **Volumetric Heat Haze; the** **Surface Grid Channel Name** is set to **Temperature_phx**, and the **Isosurface Level** is set to **0.5**. **Heat Haze** is set to **10**. **Border Fade** is set to **250**. All other options are left at their default. ## **Surface** --- --- ### Example: Isosurface Level In this example, a Phoenix *.aur* file of a liquid simulation is connected to the **Input** parameter. The **Render Mode** is set to **Mesh**. The **Surface Channel** is set to **Grid Channel**, and the **Grid Channel Name** is set to **Temperature_phx**. **Mesh Smoothness** is set to **1**. All other parameters are left at their default state. Use the sliders to preview the Volume Grid as a mesh (when rendered) and as a voxel preview (in the viewport). Keep in mind that changes to the Rendering rollout are not reflected in the voxel preview. To change the voxel preview, use the Preview rollout. ![image](media://1513ce16-6a30-4613-bad3-ab46837e762e) ![image](media://c97b58d6-5047-4f91-a377-710fb71664a6) ![image](media://ac9faa90-7160-455d-95e0-1da5b9b393d3) ![image](media://bd24c976-86d0-4735-b323-1722da6931cb) ![image](media://44fd9caa-0d66-4deb-a780-def6c45e731c) ![image](media://14e63dd0-e3bc-4e68-bef3-c53a298f9913) ![image](media://44fd9caa-0d66-4deb-a780-def6c45e731c) ![image](media://14e63dd0-e3bc-4e68-bef3-c53a298f9913) ![image](media://ac9faa90-7160-455d-95e0-1da5b9b393d3) ![image](media://bd24c976-86d0-4735-b323-1722da6931cb) ![image](media://44fd9caa-0d66-4deb-a780-def6c45e731c) ![image](media://14e63dd0-e3bc-4e68-bef3-c53a298f9913) ![image](media://44fd9caa-0d66-4deb-a780-def6c45e731c) ![image](media://14e63dd0-e3bc-4e68-bef3-c53a298f9913)