In this video, we will take a look at the ability to render very high resolution images

together with all of their separate render elements, all done on the V-Ray RT GPU.

V-Ray RT GPU allows for rendering images regardless of their resolution.

Even when rendering ultra-high definition images V-Ray would self-adjust to keep the

GPU fully utilized and produce maximum performance.

Another optimization for high resolution rendering is that all the frame buffer information is

stored in the computer memory.

This keeps the video memory available for other resources.

We will also utilize the V-Ray render elements which could be used for greater control in compositing

They contain different shading components such as lighting, reflection, GI and so on.

When properly composited they reconstruct the original rendering.

The render elements are rendered simultaneously with the render and do not add extra render time

This way, for instance, we can see the denoiser render element update in real time during rendering

We could also add some utility render elements such as Multi Matte which allows for extracting masks

and ExtraTex - for adding a custom texture, for example VRayDirt

Another very useful render element is the LightSelect which extracts the light contribution

of a pre-selected light source.

This allows for adjustments of light’s intensity and color in post without re-rendering the image.

When using V-Ray RT GPU, all the shading components such as reflection, refraction, GI, and so on

are included in the LightSelect render element.

This is true in the case of using BF BF as our GI engine.

In future versions of V-Ray this would be supported using BF LC as well.

Let’s open up the render settings and set the desired resolution.

In this particular case let’s go for something close to 4K resolution.

Next, let’s set the engine type to CUDA, so we can render using the GPU.

We are going to render all the separate render elements and use them for compositing later.

Let’s set a destination folder where they would be saved after the rendering is finished.

Under the Frame buffer rollout click on the Separate render channels checkbox and choose

the desired destination.

Finally, under the Render Elements tab we can add all the elements we need.

In this example, we already have some.

Let’s add a couple more.

You can do that by clicking on the Add button and selecting from the list.

Let’s choose VrayLightSelect, specify a light source, and also give it a name to keep

things organized.

Another useful render element we can add is the VRayExtraTex.

We need to supply a texture to make it work.

In this example, we will plug in a VRayDirt texture.

Let’s name it appropriately and go ahead and hit the render button.

While the rendering is going on we can switch between the separate render elements and see

how each one of them progresses.

If we have set some color corrections within the frame buffer that we’d like to use later

on, we can do so by saving them to a LUT file and load them as needed.

Once the rendering process is completed, we can load all the separate render elements

and composite them in a software of choice.

In this demonstration, we are going to use Photoshop.

The first thing we will do is set the blending mode of all of the render elements to “Add”.

Let’s leave only the Light Select ones.

Let’s pick one of the lights and change its color and intensity.

Next, we can use the Multi Matte render element to mask off certain parts of the image and

make changes only to the unmasked parts.

Let’s select everything in the blue channel and make some changes to the Reflection render element.

We can easily change the hue and saturation of the reflections to achieve a certain look and feel.

Following the same logic, we can quickly change the color of the sub-surface scatter render

element as well.

Lastly, let’s add a color lookup adjustment layer and load our color corrections file

that we have exported from the V-Ray Frame Buffer earlier.

In this video, we went over rendering very high resolution images on the VRay RT GPU

and also rendering separate render elements that could be used in compositing.

I hope you have found this video useful and helpful.

Please give us your feedback, comment, or share it.

If you’d like to follow along this tutorial, please download the scene from the link provided

in the video’s description.

Make sure you check out more of the V-Ray feature videos and be on the lookout for new ones.

Thank you for watching.