Photogrammetry

RealityCapture

The software we used to create our photogrammetry model of Prospect Point is called RealityCapture. They already have many videos and tutorials for their software so below are a couple of tips and tricks we learned while using this software.

Unwrap Tool

If you click the Texture button in RealityCapture, it will unwrap it then texture in one go. If you unwrap then texture, you can see before hand how many textures will be put one.

The best way we found was using Adaptive Texel Size, setting the min as the optimal texel size and max was min * 10.

Control Points and Photos

RealityCapture works really well when taking 360 images of one object, but modelling an environment is a little trickier. This is when control points are very important. When taking your photos, make sure you a taking the photos continuously, as if you were walking down the path all while keeping in mind the control points for your environment.

It's good establish what your control points should be before taking the photos. It is also very helpful to have stickers or some sort of marker to indicate what the control points are so when you are taking the photos you can capture it easily. The stickers or indicators make it much easier to establish control points later on in RealityCapture.

You can also predetermine the distance between two established control points before hand to have a sense of scale for your model.

Cleaning Up the Models

The simplifying tool in RealityCapture would oversimplify the vegetation and benches in the model and not really simplify the floor. We weren't very satisfied with the simplification tool in RealityCapture. So we experimented with Blender, Autodesk Maya, and 3D Studio Max to simplify the model. Below is a short description of the cleaning and simplification process.

Both Blender and Maya could not handle the high polygon count of the model so we ended up using 3D Studio Max for clean up.

RealityCapture

First, we did an initial clean up with RealityCature's filter tool. This got rid of all the excess noise in the background. Then, we simplified the models from 100 million triangles to around 3 million triangles. These models were then imported into 3D Studio Max for further simplification.

3D Studio Max

Clean Up

we deleted all the big trees because they didn't come out very nice, we planed to replace them using Unity's SpeedTree
got rid of lots of big random triangles and loose geometry
filled in any holes
smoothed out the floor, some bits from RealityCapture turned out a little uneven

Simplification

we separated the model into Front Vegetation, Back Vegetation, Benches, Floor, Landmarks and Fences.
We the simplified using the Pro Optimizer modifier in 3D Studio Max
each section was simplified differently, floor was 10%, front vegetation 40%, benches and fences were 30%, landmarks 50%, back vegetation 5% and so on
make sure you only check "exclude borders"

Combining and Aligning

once the simplification was done, right click on the mesh and hit "turn into edittable mesh", this will make sure the modifiers stick
import the model that was scaled to the correct size and use it as reference, for us it was the StonePath
- the scaling was done in RealityCapture during the control point phase
import another model to align with your reference
find two points on both the models that can be matched together
go to creation -> hit the little triangle ruler -> hit Tape
measure out the two points on both models, make sure they're both in the same direction
- turn on vertex snap so your cursor snaps to each vertex
make the model you want to align with (the non- reference model) a child of its own Tape
select one end of the tape and click the Align tool
- Tools -> Align -> Align
same end of the tapes together
repeat these steps for the other end of the tape
select the non-reference model and click "affect pivot point"
- this is found under the 3rd tab on the left tool bar, right next to the rainbow
choose the align tool again and click on arrow end of the tape
- this should realign the pivot point to where you clicked
turn off the "affect pivot point" then scale model to the size of the reference
- this part will take lots of eyeballing and trial and error

Reconciling (Soft-selection) (in 3DS Max after aligning models)

- Select mesh and change to editable poly

- Enable soft selection and set the desired falloff distance

- Choose lasso select and start soft selecting, using ctrl to add on to selection

- Once desired areas are soft selected, check the "Lock Soft Selection" box

- Change to translate tool, then press F7 to lock translation to z-axis

- Move soft selected mesh until the mesh blends into the other mesh

- Rinse and repeat

Exporting

We found that exporting with the 2016 fbx settings for 3D Studio Max work the best. Remember to export the model into the same folder where all the textures are!

Unity

We used unity to finish tweaking the model. Below are some tips and tricks we did to optimise the model.

Importing Models to Unity

make sure the model and all the textures are in one folder
drag the whole folder into Unity
if materials aren't showing up, then try reexporting the model with default settings
- for 3D Studio Max, we noticed that using the 2018 software doesn't export the materials correctly so we had to use the 2016 fbx exporter

Importing into Unity (Automatically attaching texture to Material)

If you only import the fbx model into Unity, there will be no textures to match your materials and the model will have the default Unity texture
When you import the model, either bring in the whole folder with the model and the textures that are referenced
Another option is:
- Drag in all the textures into a setup like Assets/MyModels/ModelName/Textures.
- Then drag in the fbx model into Assets/MyModels/ModelName/FBXModel
- Importing the fbx will automatically create a folder with the same # of materials into Assets/MyModels/ModelName/Materials.
- This should work!

Level of Detail (LOD) Models

Since our model has around 800 textures and more than 5 million triangles, we used Unity's built in LOD function to reduce lag.

How to create LODs for a model in Unity

break the model up into smller sections, we broke Prospect Point up into around 24 sections (see picture below)
label all the sections "name_LOD0"
duplicate each section and simplify it using whatever optimising tool you have
- since we were using 3Ds Max we used the Pro Optimizer modifier and reduced each section to as low as we could without loosing textures
- usually down to 2-10%
label each new simplified section "name_LOD1"

Setting Up LODs in Unity

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