I previously posted on illusion knitting, and on one approach to designing simple patterns using the technique. The first 3 images below are of the swatch illustrating one of my hand knit patterns. 
Since I am now involved in a group interested chiefly in crochet, I got curious about executing the fabric in crochet. Part of the problem is that enough texture needs to be created to be able to read the “shadows”. I tried crocheting in different parts of the chain, around the posts in the row below, and ultimately went back to afghan stitch. I had not used the latter since making blankets first for my son, and then for my grandchildren.
the Tunisian aka afghan stitch fabric as it looks head-on 
tilted up 
to its side 
and its rear view
Those of you new to the technique can find some instruction at the Red Heart website, and in a beginning how-to video from Crochetcrowd. I used Tunisian simple and Reverse Tunisian simple stitches to create my pattern. In this technique, chart texture rows are read right to left. The return rows are not illustrated. It takes 2 passes of color one, followed by 2 passes of color 2 to complete one pattern row. Yarn is carried up the side, color is changed in the same manner as in any crochet stitch. In my test swatch, no border stitches were planned for or included. It is always wise to test the repeat in repeat before working the fabric.
two passes are needed with each color, so here is the repeat with double length columns 
A: color used B: forward and backward pass for each color C: number of passes to complete a single repeat. The highlighted box at the bottom indicates a completed single design row. Only 2 colors are in use in the swatch. I found it easier to track my work and the edges where the textures need to meet by using an additional pair of colors in the chart itself. Rather than use the crochet terminology I marked my first stitches with F and B for each color, referencing the front/ forward, and rear/ back vertical loops/ posts respectively. As one moves across the row from right to left, when the color/ texture change is reached, the yarn is brought to the front or the back as needed, and the next color/ texture is worked in the reverse post/ loop.
working in back loop only of the starting chain produces a firmer edge at the bottom of the piece 
return pass every other row, not represented in chart 
changing color 
Front, vertical loop 
Back, vertical loop
H: horizontal, V: vertical 
red indicates hook entrance through the front, green for through back vertical bars respectively, prior to working the next stitch
Both swatches were made using similar weight yarns. The crochet version required more passes back and forth than in knitting, where the work may be turned over and the texture reversed on each knit row. The knit repeat measured approximately 5.5 inches L by approximately 4W, isolating my best guess stitch number equivalent to the crochet one. The crochet swatch measures 7 inches L by 6W.
turn work over (purl side facing once again), chain 3, 2 double crochet, slip stitch into the center of chain 5 space, repeat across the knit, end with a slip stitch into last chain 5 space 
