V-Ray Lesson 8

Fake environment:
For best environment map, best to us HDRI format. Best to use when its just a separate object, not in the interior.
Go to materials, go to open library and select from the list VrayHDRI and drag to material slot.
In the browse, select the HDRi image file. By map type, select spherical environment. If you want to rotate and look around the picture, you can modify horiz. or vert. rotation.
In order to have the HDRi environment work , go to render setup, under V-RAy, option environment. Turn on sky light with a multiplier 0.3. Next turn on Reflection/refraction environment override. Next drag the material into the None box.

Blending material:
VrayBlendMtl - mostly used in industrial design by mixing a couple of layers of material.
To create it, first create a base material.
For Bronze: Use VRayMtl, have diffuse as darker green and Reflect as lighter green, Refl. glossiness of 0.75, and subdivs of 8.
As a base use the Bronze material and click on the VrayMtl and change it to VRayBlendMtl, click to keep old object, now you have a blend material with bronze as the base material.
In the first Coat Material put a VrayMtl, in diffuse, set the rust bitmap. Now select the blend amount category to assign how the rust will be distributed about the object. Click on None and apply a dirtmask bitmap.
In the second Coat Material apply another VrayMtl, in diffuse, set the dust bump. In the blend map, attach a dust bitmap.

Vray2sidedMtl:
This allows a material to pass light through itself. Important that:
1. The surface should not have any thickness.
2. One of the sides must be lit by a light source
3. Global illumination must be turned on.
To do this, select an existing material, and then click to change it to Vray2sidedMtl.
Set Translucency to about 180 (this allows the light to pass, the higher the value the more light passes). Next to go Global Illumination and turn it on.

How to make christmas lights.
This is done using a gradient map.
Pick light material, change it to Vraylightmap. Set multiplier 1.2. Next click on None and set a Gradient Map. Change Gradient Parameters. Set first to very dark green, second color place a falloff material, for fir color set a white color and second a light green and last as green. Change 2 Color Positions to 0.7.

There is a problem, the lights don't shine. Set the multiplier to 30, so that you get a reflection and a lighting effect. However, in this case, the colors fade. So to take care of this problem you have to use another material.
Vrayoverride mtl. It allows to set two materials, one will render for the light, the other for the material.
To do this, select the light material and change it to Vrayoverride.
Next copy the Base material into the GI slot as a copy. Go into GI, and set the multiplier to 35.

For a final render, set a higher picture size and in the Irradiance map, modify the preset to a medium or higher and in settings increase the noise threshold.

To set up an environment for a skylight:
Select half a sphere that works as the sky and the forest, right click and select object properties. In the general tab, uncheck receive shadow and cast shadow.
Now select the same objects, right click and select Vrayproperties. Uncheck the box visible to GI. After that, go to render setup, go to skylight, set the color to white and multiplier of 0.9. Then go to GI and turn it on.

Final exercise:
How to make a window with beautiful curtains.
Make VRayMtl, set diffuse to 200. Then go to maps, and in opacity set a bitmap of the curtain opacity. Makes sense to increase the tiling to 4x4.
Next, change the material to vray2sidedmtl and set translucency to 70, so that the light behind the curtain is high.
Next, to get rid of the fuzz on the walls (which are due to the fact that light passes via curtain).
Select the VRayLight modifier, go to parameters, exclude the curtain but only shadow casting. Now lower the multiplier to 20 and subdivs to 20.
Next, to increase the brightness on the floor, change the direct light multiplier higher to a 6.
Next, take the second texture of the curtain, change it to a vraymaterial. Then set it to a twosided material and change transparency to about 20.
Final render looks like this:

You can also set render presets.
Open render setup, scroll all the way to the right, all the way at the bottom, there is a drop down of a preset. The file is saves as an rps.