creating rug texture

[cstuartpaint]

hoping someone can help... i found an image of a rug that i used as a texture map to create the rug. it looked good, but wanted the look of piling to create depth. i added bump pattern to the material and got the look i liked in the preview- see attached. but when i rendered it, it still looked flat. also see attached quick rendering. can anyone tell me what's wrong?

[dalomar_cg]

Re: creating rug texture

Bump is essentially a "trick" where "texture" is simulated simply by changing the normals that are used to shade the surface. The main "issue" with this is that the geometry of the surface is never changed, so simulating things with more then a fine surface texture is usually pretty hard.

The solution is to use displacement instead. Displacement will actually create the geometry that the map is describing, which yields a much more convincing effect. The good news is that chances are all you need to do is change the map from being in the bump slot to the displacement slot and do a tweek on the multiplier if necessary.

[Micha_cg]

Re: creating rug texture

If the preview looks good and the rendering not, than I would change the bump intensity. The preview sphere and the model could be in different scales, so a bump can be very strong for preview, but good for rendering. I would use displacement only, if the bump looks wrong, because displacement need more render time. So, first try to get a visible bump effect, than optimize it or jump to displacement.

Also important: additional lights helps to produce a better visible effect than HDRI GI env only and the usage of the sec engine QMC produce a better effect than Irradiance Map. The reason is, that raytracing without interpolation dosn't smooth bump details, but the IM interpolation eat up the bump effect. You can find an example at my material tutorial

http://asgvis.com/index.php?option=c...d=30&Itemid=55

at the ceramic tiles section.

For small detailed rugs I wouldn't use displacement. You could add a rug structure (like attached) to the color texture map in photoshop befor. So, the bump must not do the work alone.

[dalomar_cg]

Re: creating rug texture

If the preview looks good and the rendering not, than I would change the bump intensity. The preview sphere and the model could be in different scales, so a bump can be very strong for preview, but good for rendering.

For reference I believe the preview sphere has a diameter of one unit. So if you're in millimeters the sphere will be quite big, and thusly your multiplier will have to probably be stronger. And if you're in meters then you'll probably need to go with a smaller multiplier.

You can also try Detail Enhancement within Irradiance mapping.

[cstuartpaint]

Re: creating rug texture

thanks for the responses. i will try these and see what i come up with.