How to make a tree

Introduction

Hello, in that tutorial some Zbrush plugins are requires.

http://www.pixologic.com/zbrush/downloadcenter/zplugins/

  • Decimation Master
  • Uv Master

Step by Step

Draw The Tree Shape

1. Create a tree with The Zsphere

 

 

 

 

Preview : A

Adaptive skin > Density : 1

zbrush_tree_tutorial_zphere

 

The model is composed by 8600 polygons! we will reducing the model before making the uvmap.

2. Click on Make Adaptive Skin with the density set to the level 1.

3. Click on Make Polymesh 3D

4. Save/Keep the Zsphere on the side for the rigging lately.

Reducing the Polycount

Here we will need the Decimation plugin installed.

But first, we will making the masking, this step is very important, this is the weak point of my work, i am sure that step can be improved to have a better control on the mesh density.

1. Create the masking on the thee ramification to preserve the original Shape

zbrush_tree_tutorial_masking

2. Apply the Decimation

  • I haven’t checked Freezed Border, but you can testing by yourself what option give you the result that you are happy with it .
  • I only play with the % of decimation give a low value, big value give you a poor reduction.
  • Click Pre-process or Pre-process all if you apply it on several subtools.
  • Click Decimate Current or Decimate All if you apply it on several subtools.

zbrush_tree_tutorial_pre_result

The shape looks good from there, but.. you must check every branches of the tree.

Several errors dues of the masking that can generate a bad geometry.

zbrush_tree_tutorial_reduction_errors

3. Undo the decimation and refine your mask following these  tips.

 

You must knows, that every time you change the masking, you Must absolutely, execute the Pre-Processing Current / All command.

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Tips
  • Use a little Brush Size
  • Use Lasso tool to create the mask.
  • Protect the ends of each branch from the tree, just to prevent your branches to end with a spike shape, that’s very important.

zbrush_tree_tutorial_masking_tip1

  • Improve the Base of the tree trunk.

zbrush_tree_tutorial_masking_tip3

When you get happy with the result save the model to an Obj file, we are going to fix up the mesh into an external 3d modeling software.

Fix The Topology

If you apply a subdivision on your model now, and you inspect the model, you will see something like this :

zbrush_tree_tutorial_subd_and_triangles_errors

When you subdivide a model with too much triangles the subdivision, give a bad aspect on your model. To fix the problem i only find one good solution not too long to be done with.

We will editing the model in a modeling sofware of your choice, here i used lightwave.

1. Load the Obj File into your 3d software

2. Apply a quadrangulate , with Lightwave I use the “Merge trigonX” script, but Maya or 3DSmax got the tools you need to

zbrush_tree_tutorial_merge_trigons

3. on Then branches there are several errors like this, so inspect the whole topology and then fix the issues when you found some :

zbrush_tree_tutorial_fix_topology

In Lightwave, I Used the drag tool, then “Delete polygons” and then “merge points”, to clean up a little bit the model.

4. Improve the branches subdivision before we go back with the edited model in Zbrush.

zbrush_tree_tutorial_fix_topology2

Now the model has been loaded in Zbrush, look at the result when I apply the a subdivision on the new model.

zbrush_tree_tutorial_subd_final

Now we have to create the polygroups to prepare the UV Unfolding with Uvmaster plugin.

Create the polygroups

Use the Lasso, Rectangle, Hiding tool, with Polygroups > Group Visible command.

zbrush_tree_tutorial_polygroups

Unwrapping

More details with the Uvmaster Tutorial.

zbrush_tree_tutorial_uvmap

Sculpt Techniques

Now take place for the sculpting session !

1. I begin with standard shape Brush ( add/sub )

Note : I preserve the end of the branch, or use an appropriate brush draw size on it.

zbrush_tree_tutorial_global_sculpt

2. I use the SKIN1 brush in Spray Stroke and i use various size and Z internsity

 

zbrush_tree_tutorial_sculpt_bark

Painting Techniques

Base color

1. Now I activate the polypaint by clicking on Colorize.

2. I selecting the base color of the bark on the color palette

3. Create a new layer, and rename it “base color”.

4. For the brush settings, we must to uncheck Zadd and Zsub, just enable the RGB only.

5. Color Tab > Fill Object

zbrush_tree_tutorial_fill_color_object

6. create a new layer, rename it “Cavities Depth”

7. In masking panel create a mask by cavity, tweak it has you wik and then add some variations of color tones , it will give a deeper aspect for the smalls details.

zbrush-tree-tutorial-painting-depth-layer

Using NoiseMaker

Let give a try with the noise maker. I play around with the parameters and it finally give me an acceptable aspect to make that tree bark aspect.

zbrush_tree_tutorial_with-noise

Adding More details

I added one new layer , and mask tweak by peak and valleys, then I painted some color variations here and there, using the Spray tools, and finally reduced the layer opacity a little bit.

zbrush-tree-tutorial-painting-adding-details

 

 

6. Painting Details ( RGB mode active)

 

Now you can export your normal map and your diffuse map

Enjoy the render !

IMAGE!!!

Conclusion

This tutorial is a subject to update content because of the reasons describes below :

Yes  the tutorial is old, the techniques are approximative, and the final texture look like nothing realistic, but it gives a complete workflow to create very personal trees.

All step done in Lightwave, but all can be done with any 3d modeling tools, just to cite some, : Blender,  Silo, Maya, 3dsmax or what ever you want.

you would possibly want to edit the UVmap and change the layout, before to start to paint your tree.

Another workflow to get the low polygonal model done and prevent to have to edit the model into an external 3d applications, should be the retopology tool that Zbrush offers, but i am now using 3d Coat for all my retopology works.

Next parts

The next tutorial is naturally the one that would explain how to create nice foliage to use them as clip map and how to populate your model with a set a foliage variations

If you need to create several variations of the base of your tree, you can try to edit the topology using the Rigging with the zsphere. tutorial.