Rendering Tips

Rendering Tips - These tips will help you create more effective renderings.


Rendering Tips

Use reflective surfaces for a more realistic image

Interior image with reflective surfaces
SketchUp model rendered with IRender nXt

When making your first renderings you will probably think of adding mirrors and lights, but you may ignore the value of adding reflective properties to other surfaces.

One of the best things that you can do to improve a rendering is to focus on the details. It’s the details that can increase realism of a rendering and one detail that many users over look is adding reflection to all the materials in a model that need it. Not only that, but you must also apply the correct kind and the correct intensity of a reflection to a material.

A reflective floor can make the difference between a flat image and a realistic look image. The same is true of metal, wood, plastic and other surfaces.

Items to make reflective:

  • Wood or tile floor
  • Table top
  • Door knobs and handles

other accessories.

Spending time on these details can make the difference between a boring, flat image and an engaging, realistic one.

Use Section Planes for interior renderings

Interior Image with Section Plane
SketchUp model rendered with IRender nXt

When rendering the inside of a room it is sometimes a challenge to place the camera properly.

If your renderer supports section planes, you can create realistic renderings of the room itself with a camera position outside of the room.

Here are a few options you could choose from in order to solve this problem:

  • Place the camera entirely in the room, and use a wide camera angle.
  • Place the camera outside the room and hide one wall in SketchUp.
  • Place the camera outside the room and use a section plane to remove a wall.

Read more

Use HDRi Skies to improve exterior renderings

Camper rendered with HDRi sky using IRender nXt.

HDRi skies are a great way to improve any scene you are rendering. It is a quick and accurate way to give the user a high quality background image and illuminate the scene using the HDRi light intensity and colors.

One of the benefits of HDRi skies is the fact that the background image is in the shape of a dome, providing a full 360 degree background. This means that no matter what angle you are viewing your model from, there will always be a high quality background image. This also makes them valuable for scenes which contain reflection - reflective surfaces like this Camper, or windows.

And the separate lighting channel contained in the HDRi image provides better shadows and illumination than just the sun, or plain sky. This lighting information allows some parts of the sky to illuminate the scene more than other parts even though they have the save RGB (red, blue, and green) values and look identical.

Use HDRi Skies for:

  • Background Skies
  • Background Trees and Foliage
  • Showing objects in existing Interiors
  • Realistic Lighting Effects

Use 2 Pt Perspective for elevation changes

Due to the type of default perspective that SketchUp use, sometimes buildings can become distorted. Using two point perspective can correct these types of distortions.

When looking up or down at vertical surfaces, normal perspective will distort the vertical lines and cause them to be non-vertical.

SketchUp image in normal perspective. Vertical lines angle out.
SketchUp image in 2 Pt Perspective. Vertical lines are vertical.

Two point perspective, sometimes called ‘2D’ in SketchUp, will keep the vertical lines of your model parallel to each other.

If your rendering software supports 2 pt perspective, use it for better renderings when ever you are looking up or down on models with vertical lines.

Use Lighting Channels for quick lighting adjustments

Balanced lighting using lighting channels.

Lighting Channels isolates the effect of light sources on the final rendering, so that:

  • Balance illumination in scene without adjusting individual lights.
  • Create dusk and nighttime scene by quickly lowering the intensity of sun and sky.
  • Get results faster without having to re-render the scene.
  • Read more

Use special Water Effects

SketchUp model rendered with IRender nXt

if your renderer has special procedural bump effects they can be used to make realistic water which will reflect buildings, sky and other background objects realistically.

  • Distorted reflections to represent water ripples.
  • More Realistic highlights from reflection of light.
  • Realistic transparency caused by ripples and reflection of light.

Use Self Glow for glowing objects

Self glow applied to television screen. Rendering made with IRender nXt

Self Glow illuminates a surface as if it had light shining on it, without actually making it a light.

  • Balance illumination in scene without adding additional lights.
  • More realistic signs, monitors and projection devices.
  • Faster rendering times.

Rendering possibilities

  • If your renderer supports Self Glow - making an object appear brighter without shining lights on it - use it
  • If your renderer support image or texture illumination - treating an image or textured material as a light source - then you can use that but it may slow down the rendering process.
  • If your renderer supports "Invisible" lights - objects which illuminate the scene, but do not appear in the scene - then you may be able to achieve the desired effect by placing invisible lights in front of the object.
  • If your renderer supports translucent objects - which are illuminated by lights behind them, but still appear opaque - you can place a light behind the screen to illuminate the screen and make the screen translucent.

Use Edge lines for better detail

Kitchen rendering with edge lines.
SketchUp model rendered with IRender nXt

SketchUp users are used to using edge lines for detail, but many Photorealistic renderers do not render edge lines.

If your renderer does not use edge lines, you can add them by saving a hidden-line image of the SketchUp model, and then merging it with the rendering in "multiply mode".

If your renderer does support edge lines, then you will have the added advantage that the edge lines will appear in reflections, as well as the rendering.

Use images and textures for faster rendering

Fractal Tree created with RpTreeMaker

(Not completed yet)
SketchUp, and most renderers, do an excellent job rendering images and texture materials.

For background objects, and other objects for which 3D detail is not important, use images instead.

There is a free plugin for SketchUp - RpTreeMaker - which can be used to create tree images which can speed up your rendering time.

Use Panoramic Views to reveal entire model

SketchUp model by Boothy rendered as a Panorama with IRender nXt and viewed in a web page. You can spin, zoom, look up and look down on the entire scene.

When trying to show an entire project to a client, you often use several rendered images, or an animated movie. Another option which works well for some models, is to create an interactive, 360 degree panoramic view. This can then be turned into a movie, or embedded with a view in a web page.

A Panoramic image is created by rotating the camera while rendering to create a full 360 x 360 degree image. It works best with large interiors, or with exteriors which have a central point which let you view the full model.

You can create Panoramic Views by check the make Panoramic View check box on the Render Setup Tab dialog.

You can view the flash movie made from the Panoramic image here: View Panoramic Image in Viewer