VRAY tutorial four. exterior lighting

VRAY tutorial four. exterior lighting. setting up a camera 1. Open the file tutorial4_exterior lighting.max and you should see the Farnsworth house...
Author: Monica Carson
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VRAY tutorial four.

exterior lighting.

setting up a camera 1. Open the file tutorial4_exterior lighting.max and you should see the Farnsworth house with 4 views. This is the first time I’m going to only provide the model and we’re going to set up the camera and lighting. 2. Go to the create tab and create a Vray physical camera in the plan viewport. Click to place the camera - hold - and drag to locate the camera target.

3. Set the perspective viewport to the camera by clicking the viewport name scrolling down to camera and selecting VRayCam001 as shown. 4. Select the camera and its target by the select by name tool.

5. Move it up to eye level (about 1500/1600mm) by entering the number into the z box down the bottom. This will move the camera and it’s target up in the z axis. 6. There are some camera settings we should check, by selecting the camera and the modify tab, to mimic real life camera settings and shown below, move the camera around until you get something like the shown image. daylight

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NOTE: scroll down and find the distortion slot and change it to 0.25 - this will curve the lens

creating default vray daylighting 1. Go to the create tab and the last sub panel labelled ‘systems’ and select daylight. Go ahead and locate this anywhere in the plan view to the top right of the house so the camera is looking towards it. 2. Click yes when prompted to create a physical sky in the environment map. This will mean there will be a default sky added to the background. NOTE: Get location is a great tool is you need to be super specific with where the sun is coming from - however for this tute, and to be honest in general, it isn’t that important. 3. Now we’re going to covert this to a Vray sun (right now it’s mental ray and won’t render with the Vray render engine). To do this with the sun selected click the modify tab and change Sunlight to VRaySun and Skylight to 4. You can check invisible (unlike me - whoops) this will make sure if the sun is in view and not hidden behind a building or out of the scene you won’t see it’s distinct shape in the render. My sun was outside the camera view so I didn’t notice. 5. Make sure sky model is set to CIE clear to mimic clear sun. 6. Let’s hit render and this should be your result :) Pretty gross.

global illumination. 1. The reason it looks gross and contrasty is because global illumination is not turned on. So only where light is directly hitting the building will be lit, the rest is in dark shadow. 2. Go to Vray Render Settings and into the GI tab. Check enable GI and use the following settings. The relatively high subdivs will reduce noise in the scene. NOTE: Global illumination gives us diffuse or ambient lighting. 3. Now if we hit render we get this: Simply by enabling GI

4. Ok so it seems a bit light - but you need to remember we’ve got two simple materials in the scene. With appropriate materials and proper modelling it looks much different. 5. If you want to reduce the intensity of the sun go to the Vray Lighting Lister or select the sun and change the intensity to 0.5 lets say and change the floor to a darker grey. The result is below and you can see how small manipulations can change the outcome.

6. So it’s as simple as that. Now i’m going to show you how to set up and HDRI - using a high dynamic range image to light a scene and get realistic lighting based on real world scenes. 7. Delete the sun you’ve just created (sorry - you can always save a new file as HDRI if you want to keep your sun) 8. We need to delete the environment map. Hit 8 on your keyboard and delete the DefaultVRaySun/ VRaySky map as shown.

HDRI 1. Go to the create tab and make a VRay dome light by changing the type, place it anywhere in the plan view. It really doesn’t matter where. 2. You can leave most of the settings as default but make sure invisible is checked so the dome light shape doesn’t appear in the render and the alpha channel works correctly.

3. scroll down to the texture panel and click the none button which will bring up the material/ map browser - select VRayHDRI under the VRay dropdown menu. 4. Open up the Material editior by hitting M on your keyboard. 5. Now what we want to do is drag the VRay HDRI into a material slot and instance it in. We can now edit it here and it will update it in the dome light. See over page.

6. Call it HDRI. 7. We now need to assign an image. Click the grey square with the three dots and locate the Sun Clouds HDRI I’ve provided you. NOTE: Any old photo won’t work - it needs to be an HDRI file. You can make these yourselves by it takes expensive cameras. Peter Guthrie has an excellent suite of HDRI’s available that you can buy. 8. We need to make a few changes to the file. Change the mapping type to spherical so it effectively wraps the scene. The image is very blown out so it has the power to illuminate the scene. Change the overall multipler to 0.01 and the render multiplier to 100 so you get a nice background and the same strength in the render. NOTE: Overall multiplier X Render Multiplier must = 1. Play with different values to see how it changes the render, this will be the best way to get your head around it. 9. Change in inverse gamma to 0.8 to counterbalance some of the gamma correction (2.2) we have applied by darkening how the image appears in the backgroundrather than how it illuminates the scene. 10. The final thing we need to do is instance it into the environment map. Hit 8 to do this. NOTE: If you want to ‘swivel’ the scene around and make the light come from a different direction play with the horizontal rotation of the HDRI

11. Here’s the result - with a dead simple model you can already see the difference to just using a VRAY sun. There are much more subtle shadows using the HDRI. The colour toning is different.

VRay Sun result

if you want the glass to be more transparent and not reflect as much change the reflection map to a shade of grey rather than white. The darker you go the less reflection you’ll get

Remap the sun clouds HDRI to Dusk Pink provided - this is the result. HDRI’s are especially great for getting multiple lighting scenarios super quick. Now remember - when you model up your designs in detail, add proper materials and post process this will look much better :) but not bad for a raw image! Practice, change settings and see the results. Enjoy!