Blender to SketchUp – A Workaround for Texturing Organic Shapes

Blender to SketchUp – A Workaround for Texturing Organic Shapes by Michalis Zissiou

Although Google SketchUp is one of the easiest and fastest applications for architectural modeling when it comes to organic forms, texturing and rendering organic shapes it unfortunately falls short and has not as yet solved this issue. The major problem with  SketchUp is that it triangulates things thus making it difficult for smoothing and UV mapping of textures.

The workaround I have discovered  in solving this issue is first to model organic shapes  in Blender and then bring and integrate them into Sketchup, ready for rendering. This tutorial explains the process and the settings. It starts with the model created in Blender and explains the texturing process. Finally it is imported into SketchUp ready for rendering. This tutorial does not cover the modeling itself, nor does it cover the render process. The tutorial assumes that the reader already has knowledge of box modeling in Blender. If you are a newby and you want to learn more about Blender have a look here :

Blender to SketchUp Tutorial

Image 1- Reference photo, all sides aligned using Photoshop or Gimp.

Image 2 – Start blender /User preferences / View & Controls / Turntable, Around Selection (SU style).

Image 3 – 3D Window Menus / View Properties / turn Grid Floor Off.

Image 4 – Split screen in three views, left as side [numpad3], middle as front [numpad1], right as free
Menu view: Insert as Background Image (do this in front and side view, align image by axis).

Image 5 -Box modeling: Basic tools are: [K] loop cut, [G] Grab tool, [Z] wire-frame on/off
[O] proportional fall off (when on, use the mouse wheel for the field of the tool) an important tool.

Image 6

Image 7 – (6 – 7)  Subdivide, select and Smooth as you like.

Image 8-Enter sculpture, use Grab and Smooth tool, Multires (one or two steps in this case)
set Smooth (this affects the preview or blender rendered, not the model).

Image 9 (9-10) -Delete bottom faces selecting and deleting vertices or faces.

Image 11 – UV Unwrap: Here is the moment to think how you’ll cut your texture map
Edit mode [TAB], toggle [A] to deselect everything and select a path and [ctrl+E] = mark seem (Marked seem looks like an orange line).

Image 12 - Do this in Edit Mode , Select all vertices [A], Unwrap [U].

Image 13 -Right Window = UV Editor , Edit it using [A], [G], [S], [R], [O] so to use as much space as possible, leave some space around (that’s for bleeding later).

Image 14 – Image [new] 2048 x 2048 in this case Background color similar to texture Save as file name LESS than 8 letters !!! Important when exporting as .3ds to SketchUp later.

Image 15

Image 16 (15 -16)  Lets ROCK & ROLL!  Now we have a sculpure UV unwrapped so far, using a blank texture at this time so we can preview it. Mode / Edit Mode, In Mesh Properties you can see the UV texture (name it “master”). Press ‘New’ to create another and name it “front”. In 3D window go to Edit Mode (only there unwrap works), [A] select all vertices, press [1] front view, go to UV Window Editor and choose the background photo for texture. [U] Unwrap Menu, select Project From View. UV window, [A]select, [G]Grab, [S]Scale. Now using [O] with mouse wheel and selecting a vertice, grab wireframe in appropriate place on photo, do it as best you can do (select a vertice, Grab[G] it, turning the mouse wheel, you’ll see how this affects other vertices, needs some practice but its a fantastic tool).

Image 17 – Press button to select what to see in 3D view, the other one is for the Blender
Internal Renderer.

Image 18

Image 19

Image 20 (18 -20) -Using the same method, try to create and name all other UV Projections.

Image 21

Image 22 (21 -22) -Mode/ Texture Paint, you should see something like this above - (1) target for texture painting here always “master”- (2) source for texture painting or layer to be cloned.

Image 23 – UV Editor Window/ select the 2048 x 2048 blank texture, the one we created earlier.

Image 24 – UV Editor Window / Image, select texture painting.

Image 25 – Paint Properties / Draw / Delete anything here (press the x symbol on the right), so now it says ‘add new’, leave it as it is.

Image 26 – Enable the buttons shown above.

Image 27 - (1) Target for Texture Painting (in what texture we paint) here always “master” (2) Source for Texture Painting (or layer to be cloned).  Change the source layer as you paint – when you want to project a particular side texture, check its button.

Image 28 – Brush Properties have it set at 100%  but lower when you start mixing textures, fall off to  ‘0′ for mixing
too, it helps. Source for Texture Painting (or layer to be cloned). Change the Source Layer as you paint.
When you want to project a particular side texture, check its button (see images 29 and 30 bellow).

Image 29

Image 30

Image 31 – Here is the UV Texture made from projections. Now you can turn Clone Layer Off and continue fine tuning using the stamp tool like Photoshop (left click anywhere and paint). Do this near to seams, having a Bleed 4-8. Do this to avoid gaps, (see last photo from SU preview, gaps can be seen because I forgot to do so). Save the Texture as a bmp.

Image 32

Image 33 – Texture Button [f6] / Add New Tex / Image / Don’t load anything, its already in the drop down menu.

Image 34 -Materials Button / Map Input = UV.

Image 35 – File / Export/ .3ds / Textures should be in the same directory as the .3ds file.  SU/ Import/ 3ds. Smooth faces.

Image 36

I hope you enjoyed this tutorial, but most of all, I hope you learned something useful. Whether it’s just a new way to do something you already knew how to do a different way, or a whole new skill.  Thanks for reading.

Michalis

Here are  some additional renders and work carried out by Michalis Zissiou:

Image 1 -  Blender to SketchUp – Rendered in Podium

Image 2 – Blender to SketchUp – Rendered in Podium

Image 3 – Blender to SketchUp – Rendered in Podium

Image 4- Blender to SketchUp – Rendered in Podium

Image 5 – Blender to SketchUp – Rendered in Podium

Image 6 – Blender to SketchUp – Rendered in Podium