Tips for Faster Rendering

Rendering is never fast enough – we always want better images faster. The nXt Rendering engine creates better images with more passes. But your rendering times will be faster if you can decrease the time required for each pass.

Here is a list of small tips and tricks you can use to speed up your render time, regardless of scene complexity. Check ‘em out:

If you can’t see it – hide it!

Even if you cannot see an object in the scene, it is still being considered in the program’s lighting calculations. In the interests of efficiency, it’s best if you just turn unseen objects off.

You can hide the objects, or put them into layers which are not visible.

Be efficient with your lighting

The fewer lights you have in a scene, the quicker it will be to finish rendering.

The more light sources you have, the longer it will take.

This one is pretty obvious – the more lights the scene has, the more calculations the system has to run. As all of those light reflections start to interact with each other and different parts of the scene, your render time can go up pretty rapidly.

Minimize the amount of light emitters. Sphere and dome lights are the most efficient lights to render. Material lights sometime get carried away creating many more lights than you anticipated. Use the light bulbs supplied with IRender nXt for the best results.

Remember that sometimes you can do a lot of lighting effects in post processing using an image editor such as Photoshop or GIMP.

Get rid of lights not effecting the scene

If a light is in a closed room, and does not effect the scene at all, we still need to process it.

If a light ia behind a wall, in an open room down the hall, or does not effect the scene, turn it off. Reflected light from the light may effect the scene, but if its effect is negligible it is better to turn it off.

You can hide the lights, or put them into layers which are not visible.

Keep geometry simple

As much as possible limit your face count to the minimum. the more faces the slower the rendering.

if you can use fewer faces, circle sides, or extrusion edge segments to make simpler geometry, you will vastly speed up your rendering times.

Try to render a smaller resolution

If you render at 1,024 x 768 instead or 2,048 by 1,536, your rendering will run at least times faster. These lower resolutions wil often work just as well.

Often with printing firms, they will recommend you render at 300 or more dots per inch, when 75 dots per inch will usually work quite well.

Replace high geometry items with texture images

Geometry in the background which has lots of faces can often be replaced with an image place as a texture on a face.

An example would be a picture with frame, or a bookcase on the back wall of a room. Often a prerendered image would work just as well. You can create this image in IRender nXt by rendering the room with no interior objects, and then using the rendered image as textures to replace objecst on the back wall, or even the entire wall.

Use images for trees rather than fractal trees

IRender nXt 3D Trees can have very good detail, but take time to render.

For trees in the background, using a 2D image of the tree will often work just as well.

We make that easy for you. See: Rendering Plants as 2D Images

Set reflective materials properly

Many things, such as wood floors, walls, and cabinets, reflect light. Objects in the foreground with visible reflections, and objects which reflect lights will look much better if you make them reflective.

But reflective objects which don't have anything specific to reflect will just slow down your rendering processing reflection which doesn't really effect the final image.

Use Draft Mode or Lower Resolution Renderings until you are ready for your final rendering

Rendering at 1/2 the width (and 1/2 the height) will speed up your renderings by 400%. Use lower resolutions until you are ready to create your final rendering.

Use fewer Bump Maps or other fancy material settings

Automatic bump maps are easy to turn on, and they can create a nice 3D effect. However, unless there is a light shining on an object at an angle, it may not be worth the extra processing time to process the bump map.

See: Bump Maps

Turn off Indirect Lighting if you do not need it

It will take extra time to calculate the effects of light reflecting from materials. This is not necessary, especially for exterior scenes.

Caustics will slow down your rendering times

Only use them when you really need them.

Use HDRi instead of lights

When rendering an object or isolated geometry like an office workstation, it is faster and creates a better effect if you use HDRi lighting, such as the studio lighting built into Render Plus Software.

See: Studio Quality Rendering

Analytical sky is most efficient for exteriors

IRender nXt takes into account the lighting and shadows from the sky as well as the direct sun.

The Automatic/Analytical Sky will be fastest for most exterior renderings.

See: IRender Sky Tab

Fuzzy Reflection will require more passes for a good rendering

It is a great effect for wood floors, and other surfaces reflecting light, but it will require more rendering passes to converge.

Post Processing can be used to shorten rendering times

For example, the Smoothing filters can make rendering look better sooner.

IRender nXt lets you define filters - such as the smoothing filter - which will then be automatically applied each time you render your image.

See: Image Filters

Consider rendering parts of your model and combining the results

For example, if your rendering is divided into two parts by a vertical object, you can render the left half, then render the right half, and then combine the two images for the final rendered image.