3d from a 2d paper drawing sketchup

Table of Contents

1. Introduction
2. An introduction to using different source material for modeling
   • Trace-over modeling
   • Modeling from photos
   • Applying textures from a photograph
3. Importing CAD files
   • Earlier importing a CAD file
   • Steps when importing CAD files
   • Common issues when importing a CAD file into SketchUp
4. Using CAD files for modeling
   • Using 2nd CAD linework
   • Using 3D CAD files
5. Model optimization of 3D CAD files
   • Automating polygon reduction
   • Polygon reduction software

Introduction

Now that you lot take a bones understanding of SketchUp, you demand to decide how SketchUp fits into the framework of design in your office. By its non-procedural nature, SketchUp does not require a certain series of steps to accomplish a given job. As you progress in your utilize of the software, you may notice that you use several dissimilar methods to attain a recurring task, depending upon the context of the current model. This is good, and is every bit it should be. We practise not proscribe a particular methodology or piece of work menstruation.

An introduction to using different source fabric for modeling

In that location are several workflows that can be identified as common to edifice production manufacturers. We have produced several videos which make information technology easier to explain them, and they are linked below. Existing CAD models provide very accurate geometry which makes over-modeling improvements in SketchUp far easier and quicker, using the CAD model for reference while placing new geometry. Over-modeling refers to either trace-over modeling or model optimization.

Trace-over modeling

There are two types of trace-over modeling workflows based upon the CAD input used. One is from 2D CAD files, the other is when yous use scanned images such as PNG, JPG, and PDF.

When working from 2nd CAD linework, keep the CAD import as a component which you will employ for reference when trace-over modeling.

Do not explode the CAD file to employ the linework in SketchUp. Information technology is best to create new SketchUp edges, and permit the face finder in SketchUp peel the model with faces as y'all go.

You can also model from an paradigm file. This is usually based upon traditional CAD output, which contains several 2nd views of plan, sections, and elevations of the item.

Modeling from photos

You lot can also model from a photo of a product. This is a very advanced technique and requires great care when setting up the model in the commencement place. It lends itself better to angular forms, although it can be used effectively to apply photo textures to more than organic forms.

Applying textures from a photograph

You can tweak a photograph and use it as a projected texture onto a 3D model to accomplish good graphic results. This enables y'all to add realistic visual item to areas of the model without adding to the polygon count.

Here, the photograph adds all the buttons along the arm of the chair, without having to model each push button. The cushion uses one epitome across a shine surface, rather than modeling each area of color.

This example shows how to add a picture of a faucet to a 3D model of the faucet. Paint a face with the picture as a texture. Orient the painted face to the model (using X-ray mode in SketchUp). Correct click [context click] on the confront and select Texture > Projected. Then sample the pigment, and paint information technology onto the model geometry.

Importing CAD files

Earlier importing a CAD file

Make certain there is at least one element or line in your model prior to CAD import (even a unmarried line will suffice). This will import the CAD file as a unmarried component, with its linework isolated from the residuum of the model. Watch this video of importing CAD files into SketchUp for the import file types DWG/DXF, STL, 3DS, and IFC.

Steps when importing CAD files

1. Optional: Prep the CAD file for SketchUp import.
   1. Run very big 3D files (larger than 20Mb) through a poly reducer to make modeling in SketchUp more responsive. If possible specify the granularity of the triangle export.
   2. For second files, export multiple CAD files limiting layers every bit advisable in each to manage clutter when in SketchUp. Specifically turn off all text and dimensions and their leader lines then that they do not import as linework.
2. File > Import, and set up drawing units, and decide whether to preserve the drawing origin.
3. Group the import geometry.
   1. If any geometry exists in the model, the import will get a component automatically.
   2. Lock the import geometry prior to remodeling.
4. Make at least two Scenes to control visibility of the CAD linework:
   1. import on
   2. import off
5. Delete all CAD layers moving them to Layer0 (default layer).
6. Begin trace over of the CAD edges.
7. Develop groups and components every bit you draw.
8. Assign groups and components to your layer scheme.

Mutual issues when importing a CAD file into SketchUp

Many manufacturers already accept existing second and 3D CAD files of their products, and they wish to reuse these files straight in SketchUp. There are several problems common to CAD files that make working with them directly in SketchUp problematic.

CAD file scale

Y'all have to know the original scale of the CAD file (feet, inches, metric) and so that SketchUp can be set to compensate for this during file import. In one case the file is imported into SU you can work in any units you desire, SU volition do the conversion seamlessly.

Sometimes you may find that triangles (faces) get dropped out of a file import coming from engineering CAD 3D models. If this occurs, try setting the base of operations units college for the file during import. And so if a setting of mm or inches is dropping out triangles, try importing as cm or feet.

After the file import, scale the geometry back down to bodily size. To practise this, edit into the component and measure a known edge with the Tape Measure tool, and type the correct value for the altitude measured. SketchUp will scale all elements inside the current context proportionally.

Note: When rescaling, all sub-components in the context become re-scaled and re-positioned. This does not change the actual definition of the sub-component. The sub-component definitions retain their original size, and if you lot bring 1 in from the component browser, information technology will still exist at its original size. It is best practice to right (context) click on each sub-component and select Scale definition to redefine each component'due south "native" size for future use.

CAD file origin

Many CAD files that come from civil engineering programs have their origin points set to a particular globe coordinate. Hence, your incoming geometry may exist set very far away from the electric current SketchUp origin, even though there is aught between the incoming geometry and the 'world' origin. Yous can ensure that the imported geometry is placed at the origin in SketchUp by making sure that the Preserve Drawing Origin box is not checked earlier starting the import.

Asunder edges in a CAD file

A CAD file tin can await okay and withal, for whatever reason, it can accept disconnected edges that practice not meet exactly endpoint to endpoint. In SketchUp faces are formed past a closed loop of edges that all touch endpoint to endpoint and prevarication in the same plane. When these CAD lines import into SketchUp, they will still not run into, and hence surfaces cannot exist formed from these edges, hence the import will appear to drib faces from the model.

SketchUp's face finder engine can resolve edges down to 1/ane,000 of an inch. However, for models with geometry far from the origin or with big separation of geometry inside the model, sometimes faces can driblet out during import of a file because the confront finder cannot resolve them. This is due to the compounding of floating signal number rounding, and hence the endpoints no longer match exactly to form a closed loop.

CAD files sometimes accept small edges that hang off a closed loop. These 'hanging edges' can crusade the SU face finder to fail at creating faces even though in that location is a airtight loop of edges present. For this reason, using CAD lines can exist peculiarly problematic.

CAD file layers

CAD treats lines separately from ane another based upon layering. In SketchUp, all gratis edges (those not encapsulated in a Group or Component) volition merge one with another, regardless of their layer of origin. This can cause confusion during import where lines on different layers cantankerous over i another causing merging and breaking of one some other.

A method to assistance avoid the overlapping event is to save out multiple CAD files, exporting groups of layers at a time, substantially 'presorting' your edges as they come into SU.

In SU information technology is best to model everything on Layer0. Assign layers to things only after you lot have fabricated groups and components of them.

Using CAD files for modeling

For all these types of over-modeling explained below, there are methodologies that can help with your speed and efficiency. Inferring and the Paste in Identify function are invaluable for a skilful modeling workflow. See the commodity SketchUp best practices and applied principles for a good discussion of this method. You lot should likewise consider component bureaucracy and naming within your models.

The goal is to get your products on 3D Warehouse and expose them to a globe of architects and designers. To get everybody on the same page, we have developed a checklist that should help you double-check that you've created beautiful, useful, and piece of cake-to-operate 3D Warehouse models. To get with the checklist, nosotros've too created an commodity and a video series that digs deeper into what each detail on the checklist means to help you reach the desired results.

Using second CAD linework

For all these reasons mentioned in the previous section, it is often desirable to use the 2D CAD linework import as an underlayment to the modeling procedure. We recommend that you Do not apply 2D CAD line piece of work to form faces, utilize CAD linework to trace over. Using the inference endpoints and midpoints of CAD lines allows yous to exist very precise while drawing, without merging to the CAD source linework.

Tracing over elevation of CAD lines allows you to command the minimum size of faces you lot create. You also control the number of faces used. You tin can also split up overlapping edges and faces into separate groups or components, keeping their shapes separated. This remodeling allows you to determine layering as the model evolves. Remodeling also insures that your model faces shut every bit yous wait them to, hopefully avoiding whatsoever open loop bug.

A great use of inferring is when you want to depict from an imported 2d image file to create a 3D object. Here, we hover the rectangle tool over the side of the cooling unit and hold Shift to lock to that airplane beneath. Then draw a rectangle using the CAD paradigm higher up for the reference points. The points are traced on the CAD image, and the inference lock projects them down onto the face. Entire models can be generated using this method. (also from 2d CAD vector files)

Using 3D CAD files

Source CAD files that are 3D already contain surfaces, and they come up into SU as faces. If you choose to apply the 3D CAD geometry as SU model geometry, you will need to pay particular attention to the layers coming in from CAD, and the component naming and nesting coming in from CAD. Usually 3D CAD files do non suffer from hanging edges, simply they do tend to have very dense geometry (lots of faces) and can take missing faces due to the math rounding problems discussed in a higher place.

SketchUp has the ability to hide triangle (confront) edges in a unique way, such that the face and all next faces that share its edges are treated every bit one continuous "smooth" surface. Using smooth edges on a loftier poly model transforms information technology from a blackened image to a soft shaded model. But the heavy polygon count remains.

The polygon count (number of faces) affects the production component file size. In turn, this affects the operation of whatever SketchUp model into which it is placed. In this instance, a bathroom design involving 10 faucets would add vii.3 Megabytes to the overall design file for but the faucets, whereas using a reduced poly version would just increase the design file size by 228 Kb. It does not take long for loftier poly count product files to make an AEC building blueprint file sluggish, large, and unworkable.

Model optimization of 3D CAD files

For the model optimization workflow, you supplant complex geometry with optimized geometry, thus decreasing the polygon count and hence file size. The goal here is to simplify the model geometry, while still representing the product accurately. Many CAD generated 3D models represent surfaces very accurately with very dense geometry. A minor radius tin get the same triangulation as a larger bend. Good 3D Warehouse models do not require this level of detail.

Here is a video series showing the optimization of a faucet fixture.

Within this series, several avant-garde optimization methods are explored. The method you lot use is based upon the nature of the object beingness modeled. And then to develop i product model ( eg a faucet) you may use several modeling methods, one for the handle, another for the spout, etc. The faucet series linked above shows the following methods: the Button/Pull Scale & Rotate method, Align axes & Scale method, Profile & Follow Me method, Merge Surfaces with Motion Tool method, Start chamfer method, Perimeter Profile Modeling method, and the Push/Pull & modify profile method.

Automating polygon reduction

Poly reduction (sometimes referred to as decimation or re-sampling) is very oft required when moving from technology based 3D CAD geometry into SketchUp. There are several software programs which automate poly reduction to one caste or another. The play a trick on is to have the simplified object still appear every bit close to the original as possible in particular and outline. For most hard edge blazon models where members are a specific diameter or curvature, automatic decimation degrades the exact nature of the hard edge elements, causing tubes to become serrated, and hard edges to become rounded.

Information technology is recommended that y'all model over summit of 3D CAD generated geometry, rather than using the original CAD linework for a 3D Warehouse component. Optimizing a model directly with SketchUp modeling creates a very clean and tight model, minimizing poly count and maximizing approximation of the bounds of the original product, because you are snapping to exact points on the original polygons.

In the faucet example shown above, the new faucet geometry was modeled straight over the original CAD linework, which was File > Imported and made into a group first. The CAD linework was used equally a reference when adjustment new geometry and push/ pull, move, and scale operations to each other. This allows the modeler to be authentic to the concrete dimensions and constraints of the actual product.

Run across the article: Making a detailed model in a lightweight fashion for best practices in SketchUp over modeling. The video Importing CAD files into SketchUp discusses the different types of CAD that can be brought into SketchUp.

Polygon reduction software

One handy tool for reducing polygon count is the MeshWrapper, which wraps a regular mesh grid effectually the outside of a selection of object(south). This is useful for simplifying organic products prior to poly decimation considering it distributes an even set of points beyond the choice. Another handy surfacing tool driven by paths and profiles is Curviloft or hither and hither.

Engineering science CAD files can exist simplified prior to import into SketchUp using polygon decimation software such as PolyTrans from Okino Reckoner Graphics and Simplygon Deject https://www.simplygon.com/ , and MeshLabs from SourceForge which is an open source projection. An efficient workflow is to use a combination of automated poly reduction and SketchUp modeling.

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Source: https://help.sketchup.com/en/how-model-efficiently-using-existing-2d-and-3d-sources

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