This page provides a tutorial for rendering an interior scene.


Overview


This tutorial covers global illumination settings for rendering an interior scene.  


 

 

Tutorial Assets


To download the scene used in this tutorial, click on the button below.

 

 

Part I: Adjusting the GI settings


Step 1. First render

1.1. Open the scene.

1.2. Assign V-Ray as the current renderer.

Since the default V-Ray settings are not very well suited for a fast initial preview, we'll make a few quick adjustments before the first render.

1.3. Check the Override mtl option in the Global switches rollout, click the button next to it, and select a default VRayMtl material.

1.4. Set the Image sampler type to Progressive.  This will allow fast previews, we shall change this near the end to final render quality settings.

1.5. Set the resolution to 500 x 281.

1.6. Optionally, you can turn on the Frame stamp to print the render time on the image.

1.7. Render the scene:

 

Step 2. GI preview

2.1. Turn GI on from the Indirect illumination rollout.

2.2. Select Light Cache GI as both the primary and secondary GI engine.

2.3. In the Light cache rollout, set the Subdivs to 500, since we want only a fast preview. We'll return this to 1000 for the final rendering.

2.4. Render:

 

The result is quite noisy, but it does give a good idea of what the scene lighting is like.


Step 3: Tweaks

3.1. Since the scene looks too dark, we would like to brighten it a bit. There are several ways to do this. One is to increase the power of the lights. However, this will make the directly lit areas of the image, like the patch of sunlight, too bright, while indirectly lit regions will remain relatively dark. In this case we must take care as once the materials are applied to the scene it will brighten the scene considerably.

3.2. Go to the Material Edtior and put the default VRayMtl in one of the slots (it shows up as being used in the "Environment" in the Material/Maps browser).

3.3. Make the diffuse color of the material RGB (200, 200, 200).

3.4. Render 

 

The result is much better. We still have the same amount of light entering the scene, but it is bounced around more and thus increases the overall brightness of the scene. 

At this point, you can adjust the ratio, color etc of the lights, while getting a relatively fast feedback on the lighting. 

 

Step 4: Better antialiasing and less noise

The GI looks okay now, but we still have no antialiasing, and there is noise from the area light at the window. We'll deal with those now. 

5.1. Set the Image sampler type to Bucket.

5.2. Turn GI off.

5.3. Render

 

We'll need to adjust the Noise Threshold  & Max subdivs to reduce the noise in the image.

5.4. Set the Max subdivs to 24 and the Noise Threshold to 0.002.

5.5. Render:

 

Step 6. Final rendering with GI

6.1. Turn GI on.

6.3. Render


This completes the first part of the tutorial. In the next part, we'll add the scene materials.



 

Part II: Rendering with materials


Step 1. Rendering with materials

1.1. Turn the Override mtl option in the Global switches rollout off.

1.2. Turn on the reflection/refraction Override depth limit in the same rollout.

1.3. Turn GI off.

1.4. Set the Noise threshold of the Global DMC sampler to 0.01 for faster previews.

1.5. Render:

 

 

Step 2. Preview materials with GI on

2.1. Turn GI on.

2.2. For faster previews set the primary engine to Light Cache GI.

2.3. Render:

 

At this point you can adjust your scene materials while getting fast previews of how the will look in the scene.  



Step 3. Better GI with the materials

3.1. Set the Primary engine to Brute Force 

3.2. Set the Noise threshold to 0.002.

3.3. Set the light cache Subdivs to 1000.

3.4. Set the light cache Sample size to 0.03 (this will make the light cache a little smoother and slightly faster).

3.4. Render:

 

This is the final image that we will render at full resolution in the next part.


 

Part III: Rendering the final image


We now have to render the final image. 

 

 

1.1. Set the resolution to 1280 x 720.

1.2. Press the Render button.

 


 

 

The final scene for this rendering can be found here.

 

 

 

Part IV: Post-Processing the Image


The image looks okay, but in most cases you will want it to be a little darker or a little brighter etc. Instead of changing the lights and re-rendering, you can do those adjustments in an image processing program or directly in the V-Ray VFB. For example, here I added a bit of contrast to the image & warmed the image slightly by changing its white balance from the V-Ray VFB color corrections: