Cracks in concrete, pavement, walls, etc

[jwvanderbeck]

I am really trying to beef up my skills in the area of 2d set extension and matte painting. I am admittedly very bad at creating elements from scratch, and instead try to do as much as possible by pulling pieces for other photographs.

As a result i'm finding myself at a real loss when it comes to creating things like cracks in sidewalks and roads.

I am unofficially working on the VFX310 challenge to personally challenge myself, and I want to paint in big cracks in the sidewalks and road surfaces. However I am unable to get anything that looks even remotely believable. I was wondering if anyone could share some techniques for doing so?

[jwvanderbeck]

Well with nearly 100 views and no replies, i'm guessing this is something that is thought to be dead simple, yet many people are interested in.

Here is what i've come up with, and it seems to work well on the small scale, but falls horribly short on the large scale (IE a huge tear in a road seen from above just looks wrong).

This works with a combination of layer styles, and the right brush. The layer style I hit upon early, as it was pretty obvious. But things still never looked right, and I eventually realized it was my brush. It just didn't provide a good base as it were for the effect. I've since tweaked the brush enough to provide a pretty decent effect, though it could certainly be improved.

For the layer style, you want to set the fill opacity to 0% so you just get the effect, and not the paint. Secondly, apply a Bevel and Emboss, INNER BEVEL style, Direction DOWN, and set the depth as needed for the effect. I generally had a very deep depth -- over 100%. You will also want to tweak the intensity of the highlights and shadows, and quite possibly the colors as well. I found applying a texture to the bevel helps as well, though the settings for that would vary wildly.

Unfortunately I don't know how to export out my brush by itself to share (If anyopen can tell me please do and i'll share it :) ), but here is the basics of it:

For the tip I chose a chalk tip, in my case a size 11, with a little spacing..5%

Under shape dynamics I set it to 100% size jitter, controlled by pen pressure. IMHO you can't do this with a mouse, as you need to be able to easily vary the intensity of the cracks as you draw. I set a small min diameter, of about 18-20%, with a full 100% angle jitter.

Under scattering I scatter in both axes, 150-200%. Count of 4, with a full 100% count jitter and the control for jitter set to OFF.

Under Other Dynamics this is important, I set the opacity jitter to 100% and pen pressure as well.

Using this combination of brush and layer settings, I can get fairly decent cracks..I think it gets me about 90% of the way there in the tests I did. My biggest complaint is that the highlights on the bevels created by the layer style just don't feel as real as they shoud and tend to be too perfect. I'm not sure how to fix this.

[jwvanderbeck]

Here are a few examples of the cracks i'm getting so far with this technique. Again, I feel the smaller scale ones look the best.

[nathan]

You might have a 100 views but that could mean many different things.

You have to understand that not everyone who views the thread will know the answer to your question. Also the Google, Yahoo, MSN, and other search engine bots will constitute as a thread view when obviously no one is on the other end. The 4000+ views of my plugins thread is most certainly not anywhere near the real figure of page views.

I would like to say that a vast majority of the time when a question is asked if someone else knows the answer they will reply. It is the weekend so you also need to take that into account. Mondays tend to get the vast majority of views as everyones clocking back into work and they usually visit there favorite websites.

[jwvanderbeck]

Oh no doubt what you say is true. And i'm sure if someone knows a better way (which wouldn't be hard) to do this they will post. I just figured in the meantime I would share what i've discovered over the last couple days doing this.

I'm now finding I can get real nice looking very subtle cracks, just nothing good looking for larger more obvious tears in roads and stuff.