Rendering a Background while using vray HDRI sky

[richardcousins]

Hi guys I'm wondering if you can help me.

 

The company I work for is looking to switch to using vray as our main rendering engine. We render POS displays and feel we can get better looking visuals with vray.

 

Sounds simple but the problem is that the way present our renders is rather tricky when using vray (or I find it tricky).

 

I need to be able to create a scene in vray that allows us to render small to large objects, on a grey radial gradient with an invisible floor that has a slight reflection. It needs to have good shadows so the client can see when we render elements that are spaced off. It also has to be good for rendering plastics and metals.

 

Now I will attach a test render of the current scene that I have created

 

 

 

Now this render set up has allowed me to do most of the above. One problem I am finding is when rendering plastics, because the environment is just a grey gradient theres nothing to reflect.

 

For my setup I have:

 

3 vray lights with a HDRI map in the texture slot (though the HDRI appears to do nothing).

Primary Engine is Irradiance Map

Secondary Engine is Light Cache

 

The invisible floor is:

 

A vraymaterialwrapper. Alpha set to -1. Shadows and Affect Alpha are ticketed along with Matte Surface & Matte for refl/refrac.

 

 

Is there a way I could possibly have the setup I have but with maybe a domelight with HDRI map? I did try this but then I cant see the gradient background and you can also see the invisible floor.

[Nicolai Bongard]

You can set the background to be whatever you want. When rendering with a HDRI of an environment you usually use a vray domelight, and set the mapping of the HDRI to spherical. If you are using other kinds of HDRI textures, like an HDRI of a reflector or something, you should use vray Plane lights and make sure the mapping is not set to real world units of your texture, then it should "fit" the rectangular light.

 

For all the vray light types you can set them to affect different things, like diffuse, specular and reflection, or all of them. That way you can setup a vray domelight with a spherically mapped environment hdri texture in it, and set it to only affect reflections, then it will only show up in the reflections of your objects. There is also the possibility of including/exluding specific objects for each light.

 

With all these possibilites you should be able to do whatever you want.

[jackbird]

Have you tried the various environment (reflection, skylight, etc.) overrides in the VRay tab of the render setting dialog?

 

If those don't provide enough flexibility, then you want to look into the Trace Sets feature in VRay, which in my understanding supercedes the older "Reflect/Refract priority" workflow used in VRay 2.x for accomplishing very specific reflection exclusions.

 

Other ways to approach this might be:

 

-Render a VRayExtraTex element with your background set up with a completely different material and composite

-Use State Sets to render two passes with two different material/lighting setups - one for the products and one for the floor. (If you're doing this at high volume, and you use Deadline for network render management, you could set up a Draft script that automagically does the composite for you when the render ends)

[Tom Sproule]

Hey,

 

I don't know what settings you have. It seems the first thing is to get the HDRI working.

 

It seems that you had it working as a dome light, but then turned it off as you didn't want it in the background. Instead, under options in the light you need to check 'Invisible'. Then you won't get it in the background.

 

You can then put your radial background in the Environment and Effects dialogue. To access this either press 8 or click on the 'Rendering' tab and then 'Environment...'. You can the put a bitmap in 'Background', 'Environment Map'.

 

For your floor, I know people use vraymaterialwrapper, I never do. Here's how I'd do it. Put a plane where you want to see reflections and shadows. Put a reflective material on the plane, make this a similar colour to the background, so it blends in nicely. Select the plane, right click and select 'Vray Settings'. Under 'Matte properties' turn on 'Matte object', change the 'Alpha contribution' to -1.0 and check shadows.

 

With this setting, because it uses the plane to calculate lighting you will see the plane when vray calculates the light cache and prepasses, but it will disappear when rendering the beauty render.

 

That will do it.

[Tom Sproule]

By the way, your environment bitmap will keep changing from Screen to Spherical every time you change it. It does it as it's in the Environment tab and it thinks it should be spherical. Just keep an eye on it and make sure it's set to screen.