Interior Lighting in 3ds Max with Mental Ray

In this tutorial I will  show you how you can create a realistic interior lighting using Final Gather and Ambient Occlusion. We will achieve this effect by using daylight and sky portals without any artificial light.

Step 1. Setup

First make sure that you have your units set to real world metric units.

Customize->Unit Setup->Metric (Meters).

Change renderer for production to mental ray.

Rendering->Render Setup->Common->Assign Renderer.

Step 3. Geometry

Now we need to create a room.


Click on Snaps Toggle button to turn it on, then right click and select only Grid Points.

Choose Top View (T) and create a plane 6×8 m. Click one more time on Snaps Toggle to turn it off.


Choose Snaps Toggle. This time select Vertex only. In create tab, from dropdown menu change Standard Primitives to AEC Extended. Select Top View, choose Wall and click on every corner vertex. Click on the first point one more time. When a message will appear, click OK and then right click to finish adding wall. Disable Snaps Toggle.

Set height to 2,4 m and width to 0,3 m. Select the plane. Shift-move floor upward and make a copy. This will be our ceiling. Because we are inside the room we need to rotate ceiling by 180 degrees to have normals pointing the right direction. To to this select Angle Snap Toggle and set angle to 90.


From dropdown list  change AEC Extended to Windows. Choose Snaps Toggle and select Edge/Segment only. Go to Perspective View, press F3 to choose wireframe mode. Select Casement Window. Click on the bottom of outer wall edge, while holding a mouse button move your cursor along this edge, next release a button and click on the inner bottom edge of the wall. Move cursor up and click to finish creating a window.

Don’t worry that your window doesn’t have right proportions. We can fix it now.

Go to the Modify Panel and set Height to 1,6 m, Width to 1,8 m and Depth to 0,2 m.

In the Frame Tab choose Horizontal and Vertical Width to 0,1 m and Thickness to 0,05 m.

Change glazing thickness to 0,005 m.

Leave Panel Width to 0,1 m.

In Casements change Panel Width to 0,1.

Select two casements.

Position the window on the right height. Hold Shift and drag the window as shown on the image below. When message appears, create a copy.

Select both windows and Shift move them toward opposite wall. Choose Angle Snap Toogle. Rotate two new windows by 180 degrees.

Go to the modify panel. You have there an option, where you can determine how wide windows will be open. Set two of them to 100% and you can see that there is a hole inside. First convert a wall and then windows to editable poly. If you do this in different order, the hole inside will collapse.

Step 4. Camera

Choose top view and then insert a target camera.

Choose left view (L) and move the camera a bit higher. Change position of the camera that you can see the whole room

In Modify panel change lens to 12. You can change view to camera view by pressing (C).

Step 5. Daylight

Choose Top View (T). Select Create->Systems. Click on a Daylight button

Then a message pop up – click YES.

Click and drag at the center of the room and create a compass.

Release mouse button and then click one more time to set the height of the sun. Don’t worry we will correct it later.

Press (H). Choose Daylight object. Go to Modify Panel and change:

- Daylight Parameters: Set Sunlight to mr Sun and Skylight to mr Sky. A message will pop up – click YES.

- Position: change to manual and move Daylight Sun that rays are pointing to direction of windows.

- mr Sun Basic Parameters: Multiplier to 10.

- Softness samples 32.

Step. 6. Sky Portals

To create more brighter room we need to create sky portals. One for each window. A portal have to be a bit larger than a window.  Go to Left view (L), select wireframe(F3) and create first one (Create->Lights->Photometric->mr Sky Portals). Shift move it to another window and make an instance. Select Top View (T) and move them behind windows.

Select both portals and shift drag them to opposite wall behind next two windows.

Choose two sky portals you’ve just created. Go to mirror and select Y Mirror Axis.

Set multiplier to 10. Change shadow samples to 64.

Step 7. Materials

Let’s open Material Editor and create four materials:


Create first material. Click Standard button and choose Arch and Design (mi). From templates select Satin Varnished Wood. Change glossiness to 0,8 and glossy samples to 32. Set reflectivity to 1. Click on the M Button next to color and change U and V tiling to 10. Apply the material to the object.

Window frame

Create a new material. It will be ProMaterials: Plastic/Vinyl. Change surface finish to glossy and color to white. In performance Tuning Parameters change Reflection Glossy Samples to 32. Apply this material.


Create a new material called ProMaterials: Glazing. Click on the first window, choose element selection. Select top and bottom glass and apply the material. Do this to three other objects.

Wall and ceiling

Create a new material called ProMaterials: Wall Paint. Change RGB color to (R:0,9 G:0,9 B:0,5). Apply this material to wall and ceiling.

Step 2. Final Gather

Press F10 to open Render Setup. Go to indirect illumination and enable final gather. Change FG Precision Presets to medium and Diffuse Bounces to 5.

Step 8.  Ambient Occlusion

To apply Ambient Occlusion select each material and in every one of them, except glazing go to special effect and enable Ambient Occlusion.

In ProMaterials: Wall Paint change ambient occlusion max distance to 0,04 samples 32.

Step. 9. Render