first time question, I'm trying to create a custom piece of fabric consisting of triangles of different colors like the image. The problem I am having is the design I want to make consists of 1.5" triangles for a 42" square. I could "manually" fill each shape if they were larger but, being so small it would take forever! I wanted to use a "gradient" similar to the image. Is there a way to do this using a gradient I have already selected an then pixelating it somehow? Thanks it has been stumping me! Detailed instructions if possible!
Oh, how did I not think of this before: you can absolutely use the Blend tool to create repeating triangles which have solid colors going from one shape to another, and you can duplicate this row and flip it a few times to get a good wall going. Then you can take this power to the next level and duplicate your group of blends, change the colors in harmony using the Recolor Artwork option, and do the blend again to get a large patch of color which can have plenty detailed differences while maintaining a gorgeous color relationship at large!
A vector only method
After having your wanted shape, you must do the following main steps:
1) create a seamless triangle network that well covers your shape, likely a square that has sidelength = longest dimension of your shape. Exessive size makes possible to try rotating the angle of the triangle stripes.
Delete or don't even create the exessive triangles if you have a good idea on how triangle stripes will be oriented in relative your shape. This is for keeping computer's load in control.
This maybe is hundreds of triangles, so experiment with a smaller bunch because it is difficult to adjust sizes and forms with a good control afterwards. Colors are also difficult to adjust freely afterwards except if they are, as in the example, derived from simple radial magenta-blue gradient
Triangles are most easily created by splitting a rectangle and duplicating repeatedly with Smart Guides = ON (no problem in seamless aligning). You can have a repeating set of triangle colors that will be copied to new triangles as you duplicate the set. To avoid too boring repeating patterns you can shift triangle strips, flip them and make separate changes, if needed.
For gradient based colors you need the triangles in a few greyshades because they will get their color hues from the gradient.
2) Distort the triangle network to reflect the wanted apparent 3D curvature of your shape . Use envelope distort with a mesh and use the outline of your shape as the reference. It's good to keep the shape in the top layer as visual reference and for easy selection when wanted. The mesh can be more sparse than the triangle network because thislike patterns can be approximate
Beware modifying your shape, protect its layer.
Now you should have Layer 1 (=bottom) triangles, distorted for 3D perspective) and your shape on the top layer.
3) Mask off the exessive triangles by Clipping Mask, Copy your shape onto the triangles, insert a fill color onto it, select triangles and the shape, do Object > Clipping Mask > Make. This step can't be done before step 2) because distorting would ruin your shape.
4) Highlights and shadig for 3D light. Duplicate the top layer on the top of the triangles as layer 2 , renamed to "Shading". In the Appearance panel set it to be blended as Hard Light (=part of the opacity subtab) and reduce the opacity to 70% for more subtle effect
Select a BW gradient fill for the 3D light. Preset gradient may be ok if the intended 3D appearance is close enough. High quality result for irregular surface need a Gradient Mesh (= Object > Create Gradient Mesh). Again the mesh can be more sparse than the triangle network.
5) Color Gradient. Set your shape in the top layer to have a color gradient fill. Set its Blending mode to "Hard Light" or "Color" for more saturation. Explore different opacity values.
This step is unnecessary, if gradient based color is not wanted , but clearly separate hues for the triangles = yes. In that case the separate hues should be selected as triangle fills, when duplicating the triangles, quite early to avoid massive one by one coloring the triangles .
Here is a screenshot from the development of this receipe. A few triangles, random shape - no art, only to see that it works:
In case you need zero chattery, but a plain piece of canvas as Ai file for analysis, here you are:
a Dropbox link and a photo of it
Want more saturated color? Please, open panels Layer and Appearance. Select the gradient element and in Appearence panel change it to have, instead of Hard Light, blending mode Color and increase its opacity to taste.
You can draw a gradient rectangle, rasterize it, then use the Object > Object Mosaic command to turn it into a series of rectangles. The resulting pieces will be colored with their own color. This is boring rectangles though, so you will need to engineer your own creative way to multi-select things and move them and use Pathfinder, to turn them into triangles - but it's possible! I for example, created by color rectangle grid and used a line tool to draw the diagonals (duplicated via Illustrator commands such as Transform effect) and pathfinder Divide to cut each square in diagonal triangles. Then I selected some here and there and used reflect and rotate to 'randomize' the shapes a bit.