Seamless tiling

[charliep]

Is there a way to produce a material without the tiling effect? II'm using RAC 2008 and need to produce a material to match existing. I took a photo of the stone, but when I try to apply it, it shows up like a wall of tiles. I've gone through the tutorials including ATP 165 Accurender but can't find a solution. Any ideas?

[tomnewsom]

Is there a way to produce a material without the tiling effect? II'm using RAC 2008 and need to produce a material to match existing. I took a photo of the stone, but when I try to apply it, it shows up like a wall of tiles. I've gone through the tutorials including ATP 165 Accurender but can't find a solution. Any ideas?

You'll need to edit the image in photoshop (or similar) to get rid of the seams.

[charliep]

Thanks Tom,

When you say edit the image, do you mean the original photo or the rendered Revit imgage?

[Andre Baros]

First make a backup of your photo, then open up the original photo in Photoshop and do 3 things to it.
1. Get rid of any lighting. Since you'll be adding lighting in the rendering, you don't want to mix with the lighting which was already there. Essentially you want your material to look flat.
2. Make it tile seamlessly. If you're in Photoshop, look under Filters>Other>Offset. make sure to set the edge pixels to wrap and then try to use offset values which are half of your original photo image size. This puts the edges in the middle where you can clone, paint, or cut and paste out the edges so that the stones tile seamlessly.
3. Now put the depth back in. Since in step 1 you made the material flat you'll need to make a new copy of it which will be your bump map. Make another copy of your file and make it gray scale and then increase or decrease the contrast to make a rougher or smoother stone. If it's a very rough stone than you want a high contrast bump map, if it's a smooth stone, just the opposite.

Extra Credit. After step 2 you may find that the area you took a picture of is still very obviously tiling. You could go back and take a picture of a larger area or even the whole wall or you could fake it in Photoshop. Learning to fake it is useful because you don't usually have access to the whole wall... select the whole image in photoshop and copy it to the clipboard, then make it a new pattern Edit>Define Pattern. Then open up a new file which is much bigger than the original and use the pattern stamp tool to paint your "tiles" all over. You can see now what the material would look like rendered... and use the clone, paint, and cut-n-paste tools to eliminate the repetition. Depending on the size of your original photo you'll need to play around with its resolution before you do this or the new map may get too large. Once you have your new larger area of stone, you'll need to make a new bump map.

Issues.
1. One of the most common issues you'll run into is that there was uneven light on the original stones. There are lots of tricks for addressing this, but one which works is to create duplicate layers of the same image and adjust each one to get a different area to neutral light then use layer masks to blend back together the good parts of each layer.
2. Character stones. You'll sometimes find that there is a particular stone which stands out due to color or shape. Either you'll need to eliminate it by cloning other stones over it or you'll need to do the extra credit step and only leave it in select areas of your texture.

[charliep]

Thanks Andre,

I've not really got to grips with photo editing so it looks like an interesting weekend in front of me.

[Andre Baros]

Yeah, people love to compare rendering programs, which do matter, but in the end a lot of the result comes down to Photoshop. Good textures in, good rendering out.