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VRay rendering basic Settings

2018-04-07 20:48:39

This guide, provided by Force International CG Training, roughly explains most of the VRay rendering Settings. Some very basic knowledge of 3D Studio Max is required to understand this guide. For more information on each topic, consult the online manual.


Open the Render Settings dialog box, go to the Current Renderer volume TAB and click the assign button to select the product renderer. Select VRay in the list.


After setting up VRay as the main renderer, you will notice a bunch of new volume renderers. Each volume sidebar has the word "VRay:" before its name, and VRay's rendering Settings are filled in... The next step will describe each volume sidebar in general.


VRay Frame buffer When activated, the VRay frame buffer replaces the Max virtual frame buffer. The VRay frame buffer has more options to display processing images and many interesting options. You can uncheck the "get resolution from max" option in the volume TAB to control the amount of sharpness. The "Render to V-Ray raw image file" option allows you to render a very high definition image without using up all available memory. The use of VRay frame buffers is only suitable for advanced VRay users. If you're new to VRay, don't bother being here.


VRay Global switches Here you can control and ignore most of the VRay Settings, which are mainly used to speed up test rendering. You can turn off all Displacement, Lights, Default max lights The "Don't render final image" button is used to make VRay compute only the GI(e.g. glow map) and not render the image. Not for now :-) The corresponding check box turns all reflections and refractions in the scene on or off. This is very useful for testing purposes. Max depth controls the depth of reflection and refraction (the number of reflections/refractions before the light is ignored in ray tracing processing). You can also turn off all maps (Mpas), all Filter maps... Glossy effects, such as fuzzy reflection or refraction. Turning them off greatly improves rendering speed and is very flexible when doing test rendering. Override mat can be used to give all objects in the scene the same material. Secondary ray bias: Check the manual.


Image sampler (anti-aliasing) In VRay, you can choose one of three image samplers to calculate the anti-aliasing of an image. This controls the sharpness of your image and has a huge impact on render time. Fixed rate is very fast, but in many cases it is slow. You can use it if you have a lot of glossy materials, area shadows, motion blur, etc. A higher subdivs value means better quality, more render time. Adaptive QMC is a favorite of mine. True to its name, it is an adaptive sampler that ADAPTS its calculations to the situation. It will compare the quality of pixels calculated by some limit values and determine whether it is good enough or needs more calculation. The quality of this sampler is controlled by the QMC volume sidebar (the volume sidebar below). Use this sampler if your scene has a lot of materials, area shadows, motion blur, etc., and if you want to maximize the speed and quality of the image. It takes a while to get the sampler under control, but once you do, you'll have full control of VRay with just a few clicks. Adaptive subdivision is also an adaptive approach. Although it is very fast in many cases, it can be very slow when there are a large number of effects in the scene. It also uses more memory when rendering. Use this sampler if your scene has large smooth areas (such as an interior with large white walls). The min/max level controls the quality,0/2 is a good number, and -2/-1 is good for very fast test renders. To understand the differences between the three samplers, some testing is required. The online documentation already has a very good explanation of this topic, and there are many examples to illustrate the differences. You can change the anti-aliasing filter if you have problems with some fine materials or high details in the scene. Each sampling device has its own characteristics, but it is not the purpose of this guide to explain them all. In many cases, you can ignore it and simply turn it off. Some commonly used filters: -None - mitchell netravali: Smooth results, good control - catmull rom: Very sharp (a little like the result of using 'unsharp mask' in photoshop)- soften its radius value of about 2.5 (smooth and fast)


Indirect Lighting (GI) This volume is the main option for GI(= bounce light). Like most GI renderers,VRay has a difference between first and second bounce. A simple spotlight will cast direct light. A small portion of the light that hits an object is absorbed, but the rest bounces back into the scene. This is a rally. These one bounce may hit another object and bounce again (secondary bounce) and continue until there is no energy left. Direct light and a bounce have the greatest impact on the lighting effect, because these bounces of light still have a lot of energy. So this requires very precise calculations to create realistic lighting. Secondary bounces are generally less important (light energy has mostly been absorbed and has little effect on the visual result), so in general this can be sketched out (except in indoor scenes, where secondary bounces also become important). You can choose between different primary and secondary bounce calculations, and can adjust their intensity (multiplication). The Post-processing option can reduce the saturation of GI rays, or its contrast. Defocusing is a light image processed by refracting/reflecting light. GI defocusing is defocusing created by refracting/reflecting GI rays (light bounce). Standard primary and secondary bounces do not take into account the properties of reflective/refracting materials, only the diffuse reflection properties. You need to turn them on or off with two appropriate checkboxes. A very obvious example of reflection defocusing is if you shine a spotlight on a metal ring placed on a table, you will see a light image. Refraction defocus, for example, can be produced by a glass sphere that focuses all the light passing through it, creating a very bright spot underneath. Note that when you want GI light to pass through a transparent object, you must set the 'refractive GI' defocus to open! Remember defocusing is just a name for refracted/reflected light. Because the light coming out of the max spotlight, for example, is direct light and not GI light, you also have the ability to defocus these direct rays in VRay.


Irradiance map/Quasi monte carlo/photon mapping/light cache (Irradiance map/Quasi monte carlo/photon mapping/light cache) depends on your choice of primary and secondary bounce method, the scroll bar above will appear. They are all methods of calculating GI rebound. Each has its own advantages and applications. I'll explain them in a separate guide, but it's too complicated for this basic overview. For now, keep in mind that all of these methods approximate GI lighting. GI calculations are very time consuming, which is why methods have been invented to speed up calculations by using approximations.


Defocusing Remember the direct light defocusing from step 6? Well, here you can turn them on or off, and adjust some parameters. To get a nice direct light defocus, you also need to make some adjustments in the VR light. If I had the time, I would also do a direct defocusing guide. A simple trick to remove the need for direct light defocusing is to simply not use direct lights :-) Use only GI lights, you are Indirect Illimination Roll TAB with 'refractive/reflective GI caustics', all defocus will be calculated according to your GI Settings! Of course, it's not always possible to use only GI lights...


Environment VRay allows you to override max's environment Settings with these controls. Use 'skylight' to turn on the skylight to illuminate the scene. If you put a tile on the square behind it, its color will be ignored and replaced, and the tile will be used to illuminate the scene. You need to activate GI to make the sky light visible. The sky light is not a direct light, it is actually treated as a bounce, which is why the GI must be turned on to make the sky light visible. Note that if GI is activated, Skylight is off and you put a color in the Max background, that color will be used as Skylight. The others control the reflection/refraction environment. It doesn't matter what the max environment is, your object will always reflect/refract these VRay overlay Settings. You can also place a tile on them, like the Sky Light option. Note that these Settings are not displayed on the rendered background! To display it, it must be set in the max environment.


QMC Sampler This QMC sampler can be viewed as a global quality control. It controls all parameters such as adaptive QMC AA,QMC GI, glow mapping, effects, area shading, motion blur and depth of field - anything related to quasi-Monte Carlo. The most important parameter is the Noise theshold, which controls the accuracy of all these calculations. The highest quality setting is 0.001, but of course requires the longest render time. Global subdivs multiplier can be used to reduce/increase all subdivsion parameters in the scene (glow map,QMC GI, effects, area shadow, motion blur, depth of field,...) This is great for quick test rendering.


Color mapping Color mapping can be used inside VRay to perform a bit of display processing on the image. Please consult the online manual for more information on this different type.


Cameras You can choose different types of cameras to replace the default standard Max cameras, such as fisheye lenses, spherical cameras, cylindrical cameras, etc. Please refer to the manual for more information on the different camera types. Depth of field is the effect of having the aperture of the camera open. Objects outside the focus will become blurry. The farther away the object is from focus and the larger the aperture, the blurrier the object is. Motion blur is the blur that occurs when an object is moving very fast, or when the camera is moving. These effects are based on ray tracing and cannot be copied with other tricks, so they have a big impact on rendering time.


Default displacement These parameters control the default Vraydisplacement setting. You can find more information about permutations in the online manual, and there are plenty of legends.


The Raycaster parameters are used to control the amount of memory that VRay uses for a specific scene.99% of the time you don't need to touch them. Render region divisino.X and Y control the width and height of the render block. For small render sharpness, you can reduce them, for large render sharpness you can increase their value. A square size between 32 and 128 pixels is a good value. Region sequence changes the order in which rendering blocks are rendered. Distributed rendering is the joint rendering of an image by different computers. "Previous render" controls how the last renderin the frame buffer is overwritten by a new render block. Default geometry static/dynamic: Consult the manual. Frame stamps are useful for marking render times on rendered images. Objects settings and Lights settings controls the VRay properties of scene objects and lights. You can turn on/off partial Settings for each object in the scene. Presets can hold all or some of the render Settings for easy and quick switching, such as between test Settings and high quality Settings. The VRay log is a small window that appears at render time and gives you some written feedback about the rendering process. Level controls how much feedback is typed in the window.