How to create caustics in VRay


 

 

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This tutorial is © COPYRIGHT by José María Andrés Martín (ALZHEM)
 The total or partial reproduction of this tutorial by any means is prohibited to third parties without prior written authorization from José María Andrés Martín (ALZHEM)


How to create caustics in VRay


A good caustics can give much life to a scene, because it's a real common optic effect. To create them in VRay you must follow the next steps:
 

1.- Create a simple scene, like the below one.



2.- Next, apply the materials to the objects. The floor plane have the MAX standard material, and the another three objects have a more complex material explained below.



3.- Analyzing the material apllied to the red glass sphere we can see how it's created:

  1. The "Ambient" and "Diffuse" colors are changed to a dark red.
  2. The opacity must be set up to 30, because if we move it down to 0 we can lose the shadows.
  3. The reflection map is made with a "Falloff" material, adding to the white color box the VRayMap, and selecting in it the "Reflect" checkbox.
  4. We can get the refraction adding in the refraction map another VRayMap, but this time with the "Refract" checkbox checked, and setting the filter color a lighter color than the diffuse one


Red sphere material


Map #2 (Falloff)


Map #3 (VRayMap)


Map #1 (VRayMap)


WARNING: for a good visualization of the assigned VRay materials, we previously must  select the VRay render engine like in the "How to set up the global illumination in VRay" tutorial and, after this, in the materials options select the VRay as the render engine.


4.- Create a light in the scene set in a side, for a better caustic effect.



5.- We must configure the light as in the next image.



6.- Depending the release of VRay, the light may have the "Generate caustic" checkbox activated or not. You can see it in the "Light settings..." properties of the "System" submenu.



7.- Once there, if the checkbox is not activated, put it on.

 

8.- Before launching the rendering process we must activate in the VRay menu the caustics checkbox. This option is in the "Caustics" submenu. Check this checkbox and rise the default value to a extremely high value, because the default multiplier is impossible to see. A good number is 15.000, but for this example we will set it to 110.000 to get a better look.

 

9.- This is the final render. In my PC it spends 1 minute and 48 seconds.

 

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