This is Part 2 of my tree building tutorial. you can access the other parts from the bottom of the page.
While sculpting it’s useful to have reference constantly in view. You are able to load images into the background of the Mudbox viewport, however it can be hard to see the model while you sculpt. To fix this I’ll take the image into Photoshop, split it in half and add a square of grey in the centre. In Mudbox go to the image browser, navigate to the folder where you saved the image, select the reference image and hit ‘set image plane’ (the icon with the camera).
Import the mesh from Max and press Shift+D to subdivide the mesh a couple of times, level 2 should be about right. Now use the grab tool to start sharpening up the branches and trunk. The video below shows the process of tightening up the tree and getting the basic form laid out.
You’ll notice in this video that I had some problems in the areas where the secondary branches joined the main branches. As they’re formed of 4 edges there’s just not enough enough underlying geometry for Mudbox to work with. In retrospect I think these branches should have had 8 edges around their perimeter which would have made blending and working them more successful.
Sculpting in Mudbox is a process of working your way up the subdivision levels adding more and more detail. By using the layer system you can always go back a step or decrease the effect of a certain level of sculpting. So subdivide up to about level 4 and make a new layer in the sculpt layer menu. Now start working up the roots, bulges and knots on the branches. I used the sculpt, flatten, scrape and wax tools for this process.
This video shows me working in these details
Now it’s time to really start adding details and sharpening up the form in various areas. Sub-divide up to level 6, make a new layer and start sculpting in further detail. I used the knife tool to cut in sharper edges and forms, and again lots of use of the scrape and wax tools to get those details really defined.
This video shows the process of detailing the tree.
Finally we want to add some folds and cracks into the bark. Rather than create each one by hand I created a stencil for each in Mudbox and then used them all over the tree. I created a new Mudbox scene with a plane and created some folds and bulges. I then extracted the displacement map as a 16bit TIFF and added a soft circular black border in photoshop. I saved the map out as a 16bit TIFF and brought it back into my tree scene in Mudbox using the Image Browser. By adding the image to the scene as a stencil along with the sculpt tool you can then apply the folds in various places on the tree.
You can see this process in the video below.
It’s exactly the same idea to create the cracks, again you can see this in the video below.
In case you don’t want to make your own, my stencils are linked below.
Right click and choose ‘save link’ on the images below to download the 16bit TIFF files.
At this point you should have a detailed sculpted tree. Step back down the subdivision levels by pressing PgDn and export the level 0 mesh as an FBX file.
In the next part we’ll take the low level mesh back into 3DS max and unwrap the uv’s ready for texturing.
I’m a highly experienced freelance CG & VFX Artist. In the Commercials world I’ve led many award winning projects; both as an onset VFX Supervisor and as a CG Supervisor. I’m now branching out into Film VFX and am currently at Double Negative as a 3D Generalist. read more