A 3D Product Rendering Walkthrough

Written by Rob Mcphie  |  10-03-15

A 3d product rendering enables a client to visualise their product before it goes into production, but it can be both enormously helpful and enormously complex. In this 3D product render walkthrough we’ll take a look at some of the stages involved in a builder’s catalogue rendered in 3DS Max with Mental Ray.

Firstly, I made Flat jpeg copies of the artwork relating to all surfaces of the model (including the spine). The faces where we see the page edges piled above one another would be very complex to model; instead, I scanned them, and saved them as jpegs too.

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Examining the model revealed that it could be built from scratch, so there was no need to use a stock model. This simple open catalogue model could be built by extruding two simple splines. The first step was to draw the curved ends of an open catalogue in Illustrator, which were then imported into the 3DS Max scene as splines.

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Once imported, I positioned the spline objects vertical to the scene floor. Next, in the spline’s properties the adaptive interpolation method was checked to allow smooth curves, and an Extrude Modifier added to pull the shapes into three dimensions and to the correct height, forming the open catalogue shape.

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Having creating materials for each face of the object on the right, I combined them in a Multi/Sub-Object material. The material in the first layer will be applied to the front page surface (material ID number 1). Now an Edit Poly Modifier is applied, allowing non-permanent changes to be made to the object. With the Edit Poly Modifier selected and set on ‘element/poly’, I ctrl+clicked all the polygons on the front face, and allocated them an ID number of 1. Now the Multi-Sub material layer with the ID number 1 will be applied to the model surfaces tagged with 1. This technique was used on the rest of the model, giving each surface the same material ID number as the corresponding sub-material in the Multi/Sub material.

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With model selected, I then added a UV-Map modifier, which allows more precise control over the placement of maps on the model. This feature is too complex to cover here, so if you’re unfamiliar with it, have a play with the settings and you’ll soon get the hang of the way it works. Inside the material, the map’s scale, position and tiling controls are adjusted to apply the map correctly. These map adjustments are made inside the sub-material for each of the model’s surfaces. Because I was using Mental Ray’s Arch & Design materials, the built in ambient occlusion was switched on to accentuate the model’s solidity and any points of contact. The material and mapping process was then carried out on the left side object.

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For the background, I created a concrete material, with a concrete texture from an architectural collection from Dosch Design. It’s worth remembering that an enormous range of texture maps can be found for free on the web – and some are very good quality. Scene lighting is an enormously complex subject, so I won’t go into any detail here except to say that my set up uses three mental ray area lights, which are useful for controlling ray-traced shadows. You can see some more examples of renders produced with this type of setup on our CGI samples page.

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Rendering small sections of the scene allows for testing without wasting too much time waiting for images to render. During testing, I could see that the glossiness for this viewing angle was far too high (a material setting that was left over from the catalogue’s glossy front cover material). This could be corrected by lowering the material’s reflectivity or glossiness, adding a falloff map or by several other methods.

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Once happy with the basic render, I rendered an additional ambient occlusion pass. A material override in the render settings allows the quick, temporary application of an ambient occlusion material to the whole scene. As this pass was to be used as a semi transparent blend, render time could be shortened by lowering the final gather and anti-aliasing quality.

The ambient occlusion pass was placed in a layer above the final render in Photoshop, and mixed with a Multiply blend.┬áThe Multiply blend ensures that the layer’s darker areas mix with and darken the render to increase depth, while the lighter areas have less impact. Opacity can be adjusted to provide the level of depth required (in this case, the opacity was set at 35%). A separate ambient occlusion pass is a great way to improve a render without sacrificing too much time.

Now we come to the final touches. My colour temperature and white point settings inside 3ds Max were not set correctly, giving the render a slight colour cast (a subtle colour tint across the whole image). This was easily corrected with Photoshop’s levels – quite often, the Auto Levels option will produce superb results with just one mouse click. One of the criticisms leveled against CGI images is that they can be too ‘perfect’, with their sharp edges and flat textures. One way to combat this is to use Photoshop’s lens correction filter. This simulates the slight distortion produced by a camera’s lens, in addition to slightly softening the entire image.

I hope you’ve enjoyed this walkthrough and maybe picked up a tip or two along the way. We’ll be looking at 3D rendering again soon, but in the meantime, if you’d like to ask or tell us anything, feel free to visit our Facebook page where you can find more of our 3D work.

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